diff --git a/DashWallet/Sources/Application/Syncyng Activity Monitor/SyncingActivityMonitor.swift b/DashWallet/Sources/Application/Syncyng Activity Monitor/SyncingActivityMonitor.swift
index c56a6dc03e..7eeea3521d 100644
--- a/DashWallet/Sources/Application/Syncyng Activity Monitor/SyncingActivityMonitor.swift	
+++ b/DashWallet/Sources/Application/Syncyng Activity Monitor/SyncingActivityMonitor.swift	
@@ -136,7 +136,7 @@ class SyncingActivityMonitor: NSObject, NetworkReachabilityHandling {
     @objc
     public var progress: Double = 0 {
         didSet {
-            observers.forEach { $0.syncingActivityMonitorProgressDidChange(progress) }
+            observerSnapshot().forEach { $0.syncingActivityMonitorProgressDidChange(progress) }
         }
     }
 
@@ -157,7 +157,7 @@ class SyncingActivityMonitor: NSObject, NetworkReachabilityHandling {
                                                 kSyncStateChangedNewStateKey: state,
                                             ])
 
-            observers.forEach { $0.syncingActivityMonitorStateDidChange(previousState: oldValue, state: state) }
+            observerSnapshot().forEach { $0.syncingActivityMonitorStateDidChange(previousState: oldValue, state: state) }
         }
     }
 
@@ -178,7 +178,8 @@ class SyncingActivityMonitor: NSObject, NetworkReachabilityHandling {
     private var lastPeakDate: Date?
     private var cancellables = Set<AnyCancellable>()
 
-    private lazy var observers: [SyncingActivityMonitorObserver] = []
+    private var observers: [SyncingActivityMonitorObserver] = []
+    private let observersLock = NSLock()
 
     override init() {
         super.init()
@@ -196,19 +197,32 @@ class SyncingActivityMonitor: NSObject, NetworkReachabilityHandling {
 
     @objc(addObserver:)
     public func add(observer: SyncingActivityMonitorObserver) {
+        observersLock.lock()
+        defer { observersLock.unlock() }
         observers.append(observer)
     }
 
     @objc(removeObserver:)
     public func remove(observer: SyncingActivityMonitorObserver) {
+        observersLock.lock()
+        defer { observersLock.unlock() }
         if let idx = observers.firstIndex(where: { $0 === observer }) {
             observers.remove(at: idx)
         }
     }
 
+    private func observerSnapshot() -> [SyncingActivityMonitorObserver] {
+        observersLock.lock()
+        defer { observersLock.unlock() }
+        return observers
+    }
+
     deinit {
         NotificationCenter.default.removeObserver(self)
-        NotificationCenter.default.removeObserver(reachabilityObserver!)
+        if let observer = reachabilityObserver {
+            NotificationCenter.default.removeObserver(observer)
+            reachabilityObserver = nil
+        }
     }
 
     /// ObjC-visible accessor for `.syncStateChangedNotification` (same
diff --git a/DashWallet/Sources/Categories/NumberFormatter+DashWallet.swift b/DashWallet/Sources/Categories/NumberFormatter+DashWallet.swift
index 0f570d5bb1..a6e9384052 100644
--- a/DashWallet/Sources/Categories/NumberFormatter+DashWallet.swift
+++ b/DashWallet/Sources/Categories/NumberFormatter+DashWallet.swift
@@ -44,27 +44,25 @@ extension NumberFormatter {
             return formattedString
         }
 
-        var currencySymbolRange: Range<String.Index>! = formattedString.range(of: currencySymbol)
+        var currencySymbolRange = formattedString.range(of: currencySymbol)
 
         if currencySymbolRange == nil && currencySymbol.count != numberFormatter.currencySymbol.count {
-            assertionFailure("Invalid formatted string")
+            return nil
         } else if currencySymbolRange == nil {
             currencySymbolRange = formattedString.range(of: numberFormatter.currencySymbol)
         }
 
         guard let currencySymbolRange else {
-            fatalError("Invalid formatted string")
+            return nil
         }
 
         let isCurrencySymbolAtTheBeginning = currencySymbolRange.lowerBound == formattedString.startIndex
         var currencySymbolNumberSeparator: String
 
         if isCurrencySymbolAtTheBeginning {
-            currencySymbolNumberSeparator =
-                String(formattedString[
-                    currencySymbolRange.upperBound..<formattedString
-                        .index(after: currencySymbolRange.upperBound)
-                ])
+            let separatorStart = currencySymbolRange.upperBound
+            guard separatorStart < formattedString.endIndex else { return nil }
+            currencySymbolNumberSeparator = String(formattedString[separatorStart..<formattedString.index(after: separatorStart)])
         } else {
             currencySymbolNumberSeparator =
                 String(formattedString[
@@ -85,8 +83,9 @@ extension NumberFormatter {
         var formattedSeparatorIndex: String.Index! = formattedStringWithoutCurrency.range(of: decimalSeparator)?.lowerBound
 
         if formattedSeparatorIndex == nil {
-            formattedSeparatorIndex = formattedStringWithoutCurrency.endIndex
             formattedStringWithoutCurrency = formattedStringWithoutCurrency + decimalSeparator
+            formattedSeparatorIndex = formattedStringWithoutCurrency.index(formattedStringWithoutCurrency.endIndex,
+                                                                            offsetBy: -decimalSeparator.count)
         }
 
         let formattedFractionPartRange = formattedSeparatorIndex..<formattedStringWithoutCurrency.endIndex
diff --git a/DashWallet/Sources/Infrastructure/Database/DatabaseConnection.swift b/DashWallet/Sources/Infrastructure/Database/DatabaseConnection.swift
index ac0fac8c78..8d954fa056 100644
--- a/DashWallet/Sources/Infrastructure/Database/DatabaseConnection.swift
+++ b/DashWallet/Sources/Infrastructure/Database/DatabaseConnection.swift
@@ -29,9 +29,10 @@ class DatabaseConnection: NSObject {
     var migrationManager: SQLiteMigrationManager!
 
     override init() {
-        print("SQLite: ", DatabaseConnection.storeURL().absoluteString)
+        let databaseURL = DatabaseConnection.storeURL()
+        print("SQLite: ", databaseURL.path)
         do {
-            db = try Connection(DatabaseConnection.storeURL().absoluteString)
+            db = try Connection(databaseURL.path)
             migrationManager = SQLiteMigrationManager(db: db,
                                                       migrations: DatabaseConnection.migrations(),
                                                       bundle: DatabaseConnection.migrationsBundle())
@@ -44,6 +45,12 @@ class DatabaseConnection: NSObject {
 
     @objc
     func migrateIfNeeded() throws {
+        guard let migrationManager else {
+            throw NSError(domain: "DatabaseConnection", code: 1, userInfo: [
+                NSLocalizedDescriptionKey: "The wallet database could not be opened."
+            ])
+        }
+
         if !migrationManager.hasMigrationsTable() {
             try migrationManager.createMigrationsTable()
         }
@@ -62,11 +69,8 @@ extension DatabaseConnection {
         let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
         let docsDir = dirPaths[0] as String
 
-        guard let documentsURL = URL(string: docsDir) else {
-            fatalError("could not get user documents directory URL")
-        }
-
-        return documentsURL.appendingPathComponent(kDatabaseName)
+        return URL(fileURLWithPath: docsDir, isDirectory: true)
+            .appendingPathComponent(kDatabaseName)
     }
 
     static func migrations() -> [Migration] {
diff --git a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKKeyMigrator.swift b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKKeyMigrator.swift
index d96a825e46..18528cfe96 100644
--- a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKKeyMigrator.swift
+++ b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKKeyMigrator.swift
@@ -203,6 +203,10 @@ final class SwiftDashSDKKeyMigrator: NSObject {
         network: Network,
         isImported: Bool
     ) throws -> Data {
+        guard !Thread.isMainThread else {
+            throw MigrationError.hostCreateOnMainThread
+        }
+
         let semaphore = DispatchSemaphore(value: 0)
         var result: Result<Data, Error>?
 
@@ -228,6 +232,7 @@ final class SwiftDashSDKKeyMigrator: NSObject {
 
     private enum MigrationError: LocalizedError {
         case hostCreateDidNotReturn
+        case hostCreateOnMainThread
     }
 
     // MARK: - Helpers
diff --git a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKSPVCoordinator.swift b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKSPVCoordinator.swift
index 64970ebd56..36361e11ea 100644
--- a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKSPVCoordinator.swift
+++ b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKSPVCoordinator.swift
@@ -369,7 +369,7 @@ public final class SwiftDashSDKSPVCoordinator: NSObject, ObservableObject {
                 gapLimit: CoinJoinRecovery.recoveryGapLimit)
             coinJoinRecoveryWidenedNetwork = network
             Self.logger.info(
-                "🛰️ SPVCOORD :: CJTEST coinjoin recovery gap widened on \(network.rawValue, privacy: .public) to \(CoinJoinRecovery.recoveryGapLimit, privacy: .public)")
+                "🛰️ SPVCOORD :: coinjoin recovery gap widened on \(network.rawValue, privacy: .public) to \(CoinJoinRecovery.recoveryGapLimit, privacy: .public)")
         } catch {
             Self.logger.error(
                 "🛰️ SPVCOORD :: coinjoin recovery widen failed: \(String(describing: error), privacy: .public)")
@@ -452,7 +452,7 @@ public final class SwiftDashSDKSPVCoordinator: NSObject, ObservableObject {
               let network = coinJoinRecoveryWidenedNetwork,
               network == runningNetwork else { return }
 
-        Self.logger.info("🛰️ SPVCOORD :: CJTEST coinjoin recovery scan reached .synced on \(network.rawValue, privacy: .public) — marking recovered")
+        Self.logger.info("🛰️ SPVCOORD :: coinjoin recovery scan reached .synced on \(network.rawValue, privacy: .public) — marking recovered")
         CoinJoinRecovery.shared.markRecovered(for: network)
         coinJoinRecoveryWidenedNetwork = nil
     }
diff --git a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletCreator.swift b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletCreator.swift
index 696054df27..d71521b986 100644
--- a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletCreator.swift
+++ b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletCreator.swift
@@ -154,6 +154,10 @@ final class SwiftDashSDKWalletCreator: NSObject {
         network: Network,
         isImported: Bool
     ) throws -> Data {
+        guard !Thread.isMainThread else {
+            throw CreateError.hostCreateOnMainThread
+        }
+
         let semaphore = DispatchSemaphore(value: 0)
         var result: Result<Data, Error>?
 
@@ -179,5 +183,6 @@ final class SwiftDashSDKWalletCreator: NSObject {
 
     private enum CreateError: LocalizedError {
         case hostCreateDidNotReturn
+        case hostCreateOnMainThread
     }
 }
diff --git a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletWiper.swift b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletWiper.swift
index 933cfc5233..3a3f9be765 100644
--- a/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletWiper.swift
+++ b/DashWallet/Sources/Infrastructure/SwiftDashSDK/SwiftDashSDKWalletWiper.swift
@@ -229,6 +229,14 @@ final class SwiftDashSDKWalletWiper: NSObject {
     private static func deleteWalletsFromSDK(
         _ storedWalletIdsByNetwork: [Network: Set<Data>]
     ) -> Bool {
+        // `finished.wait()` below blocks this thread until the `@MainActor`
+        // task signals it. On the main thread that task could never be
+        // scheduled, so the wait would deadlock rather than fail.
+        guard !Thread.isMainThread else {
+            logger.error("Refusing synchronous wallet deletion on the main thread")
+            return false
+        }
+
         let finished = DispatchSemaphore(value: 0)
         let result = WalletWipeResultAccumulator()
         Task { @MainActor in
diff --git a/DashWallet/Sources/Models/Coinbase/Accounts/Account/CBAccount.swift b/DashWallet/Sources/Models/Coinbase/Accounts/Account/CBAccount.swift
index 2498745ef7..5b4eddc6d0 100644
--- a/DashWallet/Sources/Models/Coinbase/Accounts/Account/CBAccount.swift
+++ b/DashWallet/Sources/Models/Coinbase/Accounts/Account/CBAccount.swift
@@ -109,7 +109,7 @@ extension CBAccount {
                      idem: UUID?) async throws -> (transaction: CoinbaseTransaction, walletId: Data) {
         // NOTE: Maybe better to get the address once and use it during the tx flow
         guard let destination = SwiftDashSDKReceiveAddressReader.receiveDestination() else {
-            fatalError("No wallet")
+            throw Coinbase.Error.unknownError
         }
 
         // TODO: disabled until Coinbase changes are clear
diff --git a/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Account/CoinbaseUserAccountData.swift b/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Account/CoinbaseUserAccountData.swift
index 6c1936c810..2f08a3dc27 100644
--- a/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Account/CoinbaseUserAccountData.swift
+++ b/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Account/CoinbaseUserAccountData.swift
@@ -37,7 +37,7 @@ struct CoinbaseUserAccountData: Codable, Identifiable {
     var iconURL: URL {
         let code = currency.code.lowercased()
         let urlString = "https://raw.githubusercontent.com/jsupa/crypto-icons/main/icons/\(code).png"
-        return URL(string: urlString)!
+        return URL(string: urlString) ?? URL(fileURLWithPath: "/")
     }
 
     var balanceString: String {
@@ -68,7 +68,7 @@ struct CoinbaseUserAccountData: Codable, Identifiable {
         }
 
         let nf = NumberFormatter.fiatFormatter(currencyCode: App.fiatCurrency)
-        return nf.string(from: fiatAmount as NSNumber)!
+        return nf.string(from: fiatAmount as NSNumber) ?? "—"
     }
 
     var plainAmount: UInt64 {
@@ -83,7 +83,8 @@ struct CoinbaseUserAccountData: Codable, Identifiable {
     var plainAmountInDash: UInt64 {
         if currencyCode == kDashCurrency { return plainAmount }
 
-        guard let dashAmount = try? Coinbase.shared.currencyExchanger.convertToDash(amount: balance.amount.decimal()!, currency: currencyCode) else {
+        guard let amount = balance.amount.decimal(),
+              let dashAmount = try? Coinbase.shared.currencyExchanger.convertToDash(amount: amount, currency: currencyCode) else {
             return 0
         }
 
diff --git a/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Base/CoinbaseAmount.swift b/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Base/CoinbaseAmount.swift
index 815e89b9fe..8bc0d7c31a 100644
--- a/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Base/CoinbaseAmount.swift
+++ b/DashWallet/Sources/Models/Coinbase/Infrastructure/API/DTOs/Base/CoinbaseAmount.swift
@@ -19,13 +19,13 @@ extension Amount {
         assert(currency != kDashCurrency)
 
         guard let decimal = amount.decimal() else {
-            fatalError("Trying to convert non number string")
+            return "—"
         }
 
         let numberFormatter = NumberFormatter.fiatFormatter(currencyCode: currency)
 
         guard let string = numberFormatter.string(from: decimal as NSNumber) else {
-            fatalError("Trying to convert non number string")
+            return "—"
         }
 
         return string
@@ -35,11 +35,11 @@ extension Amount {
         assert(currency == kDashCurrency)
 
         guard let decimal = amount.decimal() else {
-            fatalError("Trying to convert non number string")
+            return "—"
         }
 
         guard let string = NumberFormatter.dashFormatter.string(from: decimal as NSNumber) else {
-            fatalError("Trying to convert non number string")
+            return "—"
         }
 
         return string
diff --git a/DashWallet/Sources/Models/Coinbase/Infrastructure/Currency Exchanger/CoinbaseRatesProvider.swift b/DashWallet/Sources/Models/Coinbase/Infrastructure/Currency Exchanger/CoinbaseRatesProvider.swift
index 861c3b7996..f06d038c9e 100644
--- a/DashWallet/Sources/Models/Coinbase/Infrastructure/Currency Exchanger/CoinbaseRatesProvider.swift	
+++ b/DashWallet/Sources/Models/Coinbase/Infrastructure/Currency Exchanger/CoinbaseRatesProvider.swift	
@@ -45,6 +45,7 @@ extension CoinbaseRatesProvider {
 
     private func fetchPrices() {
         Task {
+            do {
             let response: BaseDataResponse<CoinbaseExchangeRate> = try await httpClient.request(.exchangeRates(kDashCurrency))
             guard let rates = response.data.rates else { return }
 
@@ -53,11 +54,14 @@ extension CoinbaseRatesProvider {
 
             for rate in rates {
                 let key = rate.key
-                let price = Decimal(string: rate.value)!
+                guard let price = Decimal(string: rate.value) else { continue }
                 array.append(.init(code: key, name: key, price: price))
             }
 
             self.updateHandler?(array)
+            } catch {
+                DWLogger.log("Coinbase exchange rates request failed: \(error.localizedDescription)")
+            }
         }
     }
 }
diff --git a/DashWallet/Sources/Models/Transactions/WalletSendService.swift b/DashWallet/Sources/Models/Transactions/WalletSendService.swift
index 2d722289a8..01c9cb46af 100644
--- a/DashWallet/Sources/Models/Transactions/WalletSendService.swift
+++ b/DashWallet/Sources/Models/Transactions/WalletSendService.swift
@@ -333,7 +333,7 @@ final class WalletSendService: NSObject {
             )
         }
 
-        Self.logger.info("💸 TXSEND :: CJTEST preparing CoinJoin sweep — balance \(amount, privacy: .public) duffs (\(Double(amount) / 1e8, privacy: .public) DASH)")
+        Self.logger.info("💸 TXSEND :: preparing CoinJoin sweep — balance \(amount, privacy: .public) duffs (\(Double(amount) / 1e8, privacy: .public) DASH)")
         try await sendAuthorizer.authorizeSend(spendAmount: amount)
 
         guard let destination = SwiftDashSDKReceiveAddressReader.receiveAddress() else {
@@ -343,13 +343,13 @@ final class WalletSendService: NSObject {
             )
         }
 
-        Self.logger.info("💸 TXSEND :: CJTEST CoinJoin sweep destination resolved \(destination, privacy: .public)")
+        Self.logger.info("💸 TXSEND :: CoinJoin sweep destination resolved \(destination, privacy: .public)")
         let txids = try SwiftDashSDKTransactionSender.sweepCoinJoin(to: destination)
         guard !txids.isEmpty else {
             // A reported-success sweep that produced no transaction is treated
             // as a failure, so the caller surfaces an error (the sweep alert)
             // rather than silently "succeeding" with the balance unchanged.
-            Self.logger.error("💸 TXSEND :: CJTEST CoinJoin sweep returned no transactions for \(amount, privacy: .public) duffs — treating as failure")
+            Self.logger.error("💸 TXSEND :: CoinJoin sweep returned no transactions for \(amount, privacy: .public) duffs — treating as failure")
             throw Self.makeError(
                 code: .coinJoinSweepUnavailable,
                 description: "CoinJoin sweep produced no transactions"
@@ -366,12 +366,12 @@ final class WalletSendService: NSObject {
         let recordedHexes: [String] = txids.map { (txid: Data) in
             txid.reversed().map { String(format: "%02x", $0) }.joined()
         }
-        Self.logger.info("💸 TXSEND :: CJTEST recorded \(txids.count, privacy: .public) sweep txid(s) in CoinJoinWithdrawalStore: \(recordedHexes.joined(separator: ","), privacy: .public)")
+        Self.logger.info("💸 TXSEND :: recorded \(txids.count, privacy: .public) sweep txid(s) in CoinJoinWithdrawalStore: \(recordedHexes.joined(separator: ","), privacy: .public)")
 
         await MainActor.run {
             SwiftDashSDKWalletState.shared.refreshCoinJoinBalance()
             let post = SwiftDashSDKWalletState.shared.coinJoinBalanceDuffs
-            Self.logger.info("💸 TXSEND :: CJTEST post-sweep CoinJoin balance \(post, privacy: .public) duffs (was \(amount, privacy: .public))")
+        Self.logger.info("💸 TXSEND :: post-sweep CoinJoin balance \(post, privacy: .public) duffs (was \(amount, privacy: .public))")
             // The per-network recovery flag is owned solely by the recovery scan-
             // completion path (SwiftDashSDKSPVCoordinator.maybeCompleteCoinJoinRecovery,
             // which marks recovered once the one-time wide scan reaches .synced). A
diff --git a/DashWallet/Sources/UI/Coinbase/Base/ViewModel+Coinbase.swift b/DashWallet/Sources/UI/Coinbase/Base/ViewModel+Coinbase.swift
index 9cd6b07efd..e486ae4361 100644
--- a/DashWallet/Sources/UI/Coinbase/Base/ViewModel+Coinbase.swift
+++ b/DashWallet/Sources/UI/Coinbase/Base/ViewModel+Coinbase.swift
@@ -65,10 +65,9 @@ extension CoinbaseTransactionSendable {
             }
         } catch {
             await MainActor.run {
-                self.transactionDelegate?.transferFromCoinbaseToWalletDidFail(with: error as! Coinbase.Error)
+                self.transactionDelegate?.transferFromCoinbaseToWalletDidFail(with: error as? Coinbase.Error ?? .unknownError)
             }
         }
     }
 }
 
-
diff --git a/DashWallet/Sources/UI/Coinbase/Custodial Swaps/Order Preview/Model/ConvertCryptoOrderPreviewModel.swift b/DashWallet/Sources/UI/Coinbase/Custodial Swaps/Order Preview/Model/ConvertCryptoOrderPreviewModel.swift
index c50bd540c1..2e39d8566e 100644
--- a/DashWallet/Sources/UI/Coinbase/Custodial Swaps/Order Preview/Model/ConvertCryptoOrderPreviewModel.swift	
+++ b/DashWallet/Sources/UI/Coinbase/Custodial Swaps/Order Preview/Model/ConvertCryptoOrderPreviewModel.swift	
@@ -91,18 +91,22 @@ extension ConvertCryptoOrderPreviewModel {
         case .origin, .purchaseAmount:
             let formatter = NumberFormatter.cryptoFormatter(currencyCode: selectedAccount.info.currencyCode, exponent: selectedAccount.info.currency.exponent)
             formatter.minimumFractionDigits = 1
-            value = formatter.string(from: Decimal(string: order.inputAmount.amount)! as NSDecimalNumber) ?? "NaN"
+            guard let amount = Decimal(string: order.inputAmount.amount) else { return "—" }
+            value = formatter.string(from: amount as NSDecimalNumber) ?? "—"
         case .destination:
             let formatter = NumberFormatter.dashFormatter
-            value = formatter.string(from: Decimal(string: order.outputAmount.amount)! as NSDecimalNumber) ?? "NaN"
+            guard let amount = Decimal(string: order.outputAmount.amount) else { return "—" }
+            value = formatter.string(from: amount as NSDecimalNumber) ?? "—"
         case .feeAmount:
             value = order.fee.formattedFiatAmount
         case .totalAmount:
-            let total = Decimal(string: order.fee.amount)! + Decimal(string: order.displayInputAmount.amount)!
+            guard let fee = Decimal(string: order.fee.amount),
+                  let input = Decimal(string: order.displayInputAmount.amount) else { return "—" }
+            let total = fee + input
             let numberFormatter = NumberFormatter.fiatFormatter(currencyCode: order.unitPrice.targetToFiat.currency)
 
             guard let string = numberFormatter.string(from: total as NSNumber) else {
-                fatalError("Trying to convert non number string")
+                return "—"
             }
 
             value = string
diff --git a/DashWallet/Sources/UI/Coinbase/Transfer Amount/Model/TransferAmountModel.swift b/DashWallet/Sources/UI/Coinbase/Transfer Amount/Model/TransferAmountModel.swift
index ad1bf8b73e..39164ebd86 100644
--- a/DashWallet/Sources/UI/Coinbase/Transfer Amount/Model/TransferAmountModel.swift	
+++ b/DashWallet/Sources/UI/Coinbase/Transfer Amount/Model/TransferAmountModel.swift	
@@ -125,7 +125,7 @@ final class TransferAmountModel: CoinbaseAmountModel, CoinbaseTransactionSendabl
                 }
             } catch let error {
                 await MainActor.run {
-                    self.delegate?.transferFromCoinbaseToWalletDidFail(with: error as! Coinbase.Error)
+                    self.delegate?.transferFromCoinbaseToWalletDidFail(with: error as? Coinbase.Error ?? .unknownError)
                 }
             }
         }
diff --git a/DashWallet/Sources/UI/CrowdNode/Online/OnlineAccountEmailController.swift b/DashWallet/Sources/UI/CrowdNode/Online/OnlineAccountEmailController.swift
index 76ebc93790..3dcc13f7a3 100644
--- a/DashWallet/Sources/UI/CrowdNode/Online/OnlineAccountEmailController.swift
+++ b/DashWallet/Sources/UI/CrowdNode/Online/OnlineAccountEmailController.swift
@@ -102,7 +102,7 @@ final class OnlineAccountEmailController: UIViewController {
             .sink { [weak self] error in
                 if error is CrowdNode.Error {
                     self?.viewModel.clearError()
-                    self?.navigationController?.toErrorScreen(error: error as! CrowdNode.Error)
+                    self?.navigationController?.toErrorScreen(error: error as? CrowdNode.Error ?? .messageStatus(error: error.localizedDescription))
                 }
             }
             .store(in: &cancellableBag)
diff --git a/DashWallet/Sources/UI/CrowdNode/Portal/CrowdNodePortalViewController.swift b/DashWallet/Sources/UI/CrowdNode/Portal/CrowdNodePortalViewController.swift
index 5f5afd0c87..3ce47eb57d 100644
--- a/DashWallet/Sources/UI/CrowdNode/Portal/CrowdNodePortalViewController.swift
+++ b/DashWallet/Sources/UI/CrowdNode/Portal/CrowdNodePortalViewController.swift
@@ -187,7 +187,7 @@ extension CrowdNodePortalController {
             .sink(receiveValue: { [weak self] error in
                 if error is CrowdNode.Error {
                     self?.viewModel.clearError()
-                    self?.navigationController?.toErrorScreen(error: error as! CrowdNode.Error)
+                    self?.navigationController?.toErrorScreen(error: error as? CrowdNode.Error ?? .messageStatus(error: error.localizedDescription))
                 }
             })
             .store(in: &cancellableBag)
diff --git a/DashWallet/Sources/UI/Explore Dash/Merchants & ATMs/List/ExplorePointOfUseListViewController.swift b/DashWallet/Sources/UI/Explore Dash/Merchants & ATMs/List/ExplorePointOfUseListViewController.swift
index 97daeb1f57..0391f1b514 100644
--- a/DashWallet/Sources/UI/Explore Dash/Merchants & ATMs/List/ExplorePointOfUseListViewController.swift	
+++ b/DashWallet/Sources/UI/Explore Dash/Merchants & ATMs/List/ExplorePointOfUseListViewController.swift	
@@ -190,22 +190,16 @@ class ExplorePointOfUseListViewController: UIViewController {
             wSelf.updateEmptyResultsForFilters()
         }
 
-        model.nextPageDidLoaded = { [weak self] offset, count in
+        model.nextPageDidLoaded = { [weak self] _, _ in
             guard let wSelf = self else { return }
 
-            var indexPathes: [IndexPath] = Array()
-            indexPathes.reserveCapacity(count)
-
-            let start = offset
-            let total = (offset+count)
-            for i in start..<total {
-                indexPathes.append(.init(row: i, section: ExplorePointOfUseSections.items.rawValue))
-            }
-
-            wSelf.tableView.beginUpdates()
-            wSelf.tableView.insertRows(at: indexPathes, with: .top)
-            wSelf.tableView.reloadSections([ExplorePointOfUseSections.nextPage.rawValue], with: .none)
-            wSelf.tableView.endUpdates()
+            // The request may finish after a filter/search/location update has
+            // replaced the data source. Reconcile from the current model rather
+            // than applying stale pager indexes in a UITableView batch update.
+            wSelf.tableView.reloadSections([
+                ExplorePointOfUseSections.items.rawValue,
+                ExplorePointOfUseSections.nextPage.rawValue
+            ], with: .none)
         }
 
         configureHierarchy()
diff --git a/DashWallet/Sources/UI/Explore Dash/Views/DashSpend/DashSpendPayViewModel.swift b/DashWallet/Sources/UI/Explore Dash/Views/DashSpend/DashSpendPayViewModel.swift
index 7671485f15..ac6c812f1b 100644
--- a/DashWallet/Sources/UI/Explore Dash/Views/DashSpend/DashSpendPayViewModel.swift	
+++ b/DashWallet/Sources/UI/Explore Dash/Views/DashSpend/DashSpendPayViewModel.swift	
@@ -328,7 +328,17 @@ class DashSpendPayViewModel: NSObject, ObservableObject, NetworkReachabilityHand
 
             // PiggyCards returns a simple address and amount, not a BIP70 URL
             // Convert DASH amount to satoshis (1 DASH = 100,000,000 satoshis)
-            let dashAmountInSatoshis = UInt64(giftCardInfo.amount * 100_000_000)
+            guard giftCardInfo.amount.isFinite,
+                  giftCardInfo.amount >= 0 else {
+                throw DashSpendError.paymentProcessingError("Invalid gift card amount")
+            }
+
+            let satoshis = NSDecimalNumber(decimal: Decimal(giftCardInfo.amount) * Decimal(100_000_000))
+            guard satoshis.compare(NSDecimalNumber.zero) != .orderedAscending,
+                  satoshis.compare(NSDecimalNumber(value: UInt64.max)) != .orderedDescending else {
+                throw DashSpendError.paymentProcessingError("Gift card amount is out of range")
+            }
+            let dashAmountInSatoshis = satoshis.uint64Value
 
             // Use sendCoins directly with address and amount
             // This will properly trigger PIN authorization
diff --git a/DashWallet/Sources/UI/Home/HomeViewController.swift b/DashWallet/Sources/UI/Home/HomeViewController.swift
index 9bfb12a2be..0a7cf66346 100644
--- a/DashWallet/Sources/UI/Home/HomeViewController.swift
+++ b/DashWallet/Sources/UI/Home/HomeViewController.swift
@@ -523,7 +523,7 @@ class HomeViewController: DWBasePayViewController, NavigationBarDisplayable {
             textBlock1: String(format: NSLocalizedString("You have %@ in CoinJoin mixed coins. CoinJoin is no longer supported — move them to your spendable balance.", comment: "CoinJoin"), amount),
             positiveButtonText: NSLocalizedString("Move funds", comment: "CoinJoin"),
             positiveButtonAction: {
-                DWLogger.log("CJTEST HomeViewController: sweep invoked from Home popup (\(amount))")
+                DWLogger.log("HomeViewController: sweep invoked from Home popup (\(amount))")
                 self.viewModel.showCoinJoinSweepDialog = false
                 Task { @MainActor in
                     // The post-sync popup (ModalDialog) is mid-dismissal here —
diff --git a/DashWallet/Sources/UI/Home/Views/HomeViewModel.swift b/DashWallet/Sources/UI/Home/Views/HomeViewModel.swift
index bb560f9b74..12605ee9f2 100644
--- a/DashWallet/Sources/UI/Home/Views/HomeViewModel.swift
+++ b/DashWallet/Sources/UI/Home/Views/HomeViewModel.swift
@@ -372,6 +372,11 @@ class HomeViewModel: ObservableObject {
             self.isReloading = true
             DWLogger.log("HomeViewModel: Starting full transaction reload")
 
+            // SwiftUI mutates the filter on the main thread. Snapshot it once
+            // before doing the worker-queue computation instead of reading the
+            // published property concurrently during the reload.
+            let selectedFilters = DispatchQueue.main.sync { self.selectedFilters }
+
             let transactions = transactionSource.allTransactions
             // Reconcile restored Shielded → Core destinations before Core rows
             // are filtered/classified. The activity projection can recover a
@@ -397,7 +402,7 @@ class HomeViewModel: ObservableObject {
             var items: [TransactionListDataItem] = transactions.compactMap { wrappedTx -> TransactionListDataItem? in
                 Tx.shared.updateRateIfNeeded(for: wrappedTx)
 
-                if !self.passesFilter(transaction: wrappedTx, selected: self.selectedFilters, hasRewards: hasRewards, hasMasternodes: hasMasternodes, giftCardTxIds: giftCardTxIds) {
+                if !self.passesFilter(transaction: wrappedTx, selected: selectedFilters, hasRewards: hasRewards, hasMasternodes: hasMasternodes, giftCardTxIds: giftCardTxIds) {
                     return nil
                 }
 
@@ -435,7 +440,7 @@ class HomeViewModel: ObservableObject {
             for shielded in shieldedItems {
                 guard self.passesShieldedFilter(
                     item: shielded,
-                    selected: self.selectedFilters,
+                    selected: selectedFilters,
                     hasRewards: hasRewards,
                     hasMasternodes: hasMasternodes)
                 else { continue }
@@ -450,7 +455,7 @@ class HomeViewModel: ObservableObject {
             for platform in platformItems {
                 guard self.passesCategoryFilter(
                     categories: [.received],
-                    selected: self.selectedFilters,
+                    selected: selectedFilters,
                     hasRewards: hasRewards,
                     hasMasternodes: hasMasternodes)
                 else { continue }
@@ -530,20 +535,23 @@ class HomeViewModel: ObservableObject {
                 return
             }
 
+            let selectedFilters = DispatchQueue.main.sync { self.selectedFilters }
+            let historyFlags = DispatchQueue.main.sync { (self.hasRewardsHistory, self.hasMasternodeHistory) }
+
             // A coinbase / masternode tx arriving incrementally unlocks its
             // filter row without waiting for the next full reload.
-            if tx.isCoinbaseTransaction && !self.hasRewardsHistory {
+            if tx.isCoinbaseTransaction && !historyFlags.0 {
                 DispatchQueue.main.async {
                     self.hasRewardsHistory = true
                 }
             }
-            if tx.isMasternodeTransaction && !self.hasMasternodeHistory {
+            if tx.isMasternodeTransaction && !historyFlags.1 {
                 DispatchQueue.main.async {
                     self.hasMasternodeHistory = true
                 }
             }
 
-            if !self.passesFilter(transaction: tx, selected: self.selectedFilters, hasRewards: self.hasRewardsHistory, hasMasternodes: self.hasMasternodeHistory) {
+            if !self.passesFilter(transaction: tx, selected: selectedFilters, hasRewards: historyFlags.0, hasMasternodes: historyFlags.1) {
                 return
             }
 
@@ -570,7 +578,8 @@ class HomeViewModel: ObservableObject {
                 var oldItemIndex: Int? = nil
                 var oldDateKey: String? = nil
 
-                for (gIdx, group) in self.txItems.enumerated() {
+                let currentGroups = DispatchQueue.main.sync { self.txItems }
+                for (gIdx, group) in currentGroups.enumerated() {
                     if let iIdx = group.items.firstIndex(where: { $0.id == itemId }) {
                         oldGroupIndex = gIdx
                         oldItemIndex = iIdx
@@ -629,7 +638,7 @@ class HomeViewModel: ObservableObject {
                         DispatchQueue.main.async {
                             guard groupIndex < self.txItems.count,
                                   itemIndex < self.txItems[groupIndex].items.count else { return }
-                            let updatedGroup = self.txItems[groupIndex]
+                            var updatedGroup = self.txItems[groupIndex]
                             var updatedItems = updatedGroup.items
                             updatedItems[itemIndex] = txItem
                             updatedGroup.items = updatedItems
@@ -642,26 +651,22 @@ class HomeViewModel: ObservableObject {
                 self.txByHash[itemId] = txItem
                 let shouldShowReclassify = self.shouldDisplayReclassifyTransaction && tx.date > reclassifyTransactionsActivatedAt
 
-                if let groupIndex = self.txItems.firstIndex(where: { $0.id == newDateKey }) {
-                    // Add to an existing date group
-                    DispatchQueue.main.async {
-                        self.txItems[groupIndex].items.append(txItem)
-                        self.txItems[groupIndex].items.sort { $0.date > $1.date }
-                        self.showReclassifyTransaction = shouldShowReclassify ? tx : nil
-                    }
-                } else {
-                    // Create a new date group
-                    let newGroup = TransactionGroup(id: newDateKey, date: txItem.date, items: [txItem])
-                    let insertIndex = self.txItems.firstIndex(where: { $0.date < txItem.date })
-
-                    DispatchQueue.main.async {
+                // Re-check the current data source inside the main-queue hop;
+                // a full reload may replace all groups between these queues.
+                DispatchQueue.main.async {
+                    if let currentGroupIndex = self.txItems.firstIndex(where: { $0.id == newDateKey }) {
+                        self.txItems[currentGroupIndex].items.append(txItem)
+                        self.txItems[currentGroupIndex].items.sort { $0.date > $1.date }
+                    } else {
+                        let newGroup = TransactionGroup(id: newDateKey, date: txItem.date, items: [txItem])
+                        let insertIndex = self.txItems.firstIndex(where: { $0.date < txItem.date })
                         if let index = insertIndex {
                             self.txItems.insert(newGroup, at: index)
                         } else {
                             self.txItems.append(newGroup)
                         }
-                        self.showReclassifyTransaction = shouldShowReclassify ? tx : nil
                     }
+                    self.showReclassifyTransaction = shouldShowReclassify ? tx : nil
                 }
             }
         }
@@ -763,7 +768,7 @@ extension HomeViewModel {
     /// launch until the user sweeps, then self-stops (balance → 0). The durable
     /// Settings row covers the same action for users who dismiss it.
     func maybeShowCoinJoinSweepDialog() {
-        DWLogger.log("CJTEST HomeViewModel: sweep dialog check — \(coinJoinSweepAmountDuffs) duffs (\(String(format: "%.6f", Double(coinJoinSweepAmountDuffs) / Double(kOneDash))) DASH), threshold \(CoinJoinRecovery.recoveryDustThresholdDuffs), above=\(coinJoinSweepAmountDuffs > CoinJoinRecovery.recoveryDustThresholdDuffs), syncDone=\(syncModel.state == .syncDone), alreadyShown=\(coinJoinSweepDialogShown)")
+        DWLogger.log("HomeViewModel: sweep dialog check — \(coinJoinSweepAmountDuffs) duffs (\(String(format: "%.6f", Double(coinJoinSweepAmountDuffs) / Double(kOneDash))) DASH), threshold \(CoinJoinRecovery.recoveryDustThresholdDuffs), above=\(coinJoinSweepAmountDuffs > CoinJoinRecovery.recoveryDustThresholdDuffs), syncDone=\(syncModel.state == .syncDone), alreadyShown=\(coinJoinSweepDialogShown)")
         guard !coinJoinSweepDialogShown,
               syncModel.state == .syncDone,
               coinJoinSweepAmountDuffs > CoinJoinRecovery.recoveryDustThresholdDuffs else { return }
@@ -780,7 +785,7 @@ extension HomeViewModel {
             _ = try await WalletSendService.shared.sweepCoinJoin()
             return nil
         } catch {
-            DWLogger.log("CJTEST HomeViewModel: sweep (home popup) failed: \(error)")
+            DWLogger.log("HomeViewModel: sweep (home popup) failed: \(error)")
             // nil when the user cancelled auth; a message on real failures.
             return WalletSendService.coinJoinSweepUserMessage(for: error)
         }
diff --git a/DashWallet/Sources/UI/Home/Views/TransactionListDataItem.swift b/DashWallet/Sources/UI/Home/Views/TransactionListDataItem.swift
index 3eac685456..3999ab83dd 100644
--- a/DashWallet/Sources/UI/Home/Views/TransactionListDataItem.swift
+++ b/DashWallet/Sources/UI/Home/Views/TransactionListDataItem.swift
@@ -15,7 +15,7 @@
 //  limitations under the License.
 //
 
-class TransactionGroup: Identifiable {
+struct TransactionGroup: Identifiable {
     let id: String
     let date: Date
     var items: [TransactionListDataItem]
diff --git a/DashWallet/Sources/UI/Menu/Settings/SettingsMenuViewModel.swift b/DashWallet/Sources/UI/Menu/Settings/SettingsMenuViewModel.swift
index e061dac7fa..4c50d1bc7e 100644
--- a/DashWallet/Sources/UI/Menu/Settings/SettingsMenuViewModel.swift
+++ b/DashWallet/Sources/UI/Menu/Settings/SettingsMenuViewModel.swift
@@ -178,11 +178,11 @@ class SettingsMenuViewModel: ObservableObject {
     /// BIP44 address → sweep → balance refresh). The "Move CoinJoin Funds"
     /// row self-removes once the refreshed balance drops below the threshold.
     func performCoinJoinSweep() async {
-        DWLogger.log("CJTEST SettingsMenuViewModel: sweep invoked from Settings menu (\(coinJoinLeftoverFormatted))")
+        DWLogger.log("SettingsMenuViewModel: sweep invoked from Settings menu (\(coinJoinLeftoverFormatted))")
         do {
             _ = try await WalletSendService.shared.sweepCoinJoin()
         } catch {
-            DWLogger.log("CJTEST SettingsMenuViewModel: sweep failed: \(error)")
+            DWLogger.log("SettingsMenuViewModel: sweep failed: \(error)")
             // Auth-cancel is an expected no-op (nil message); a real failure
             // surfaces an alert. The row stays visible so the user can retry.
             coinJoinSweepErrorMessage = WalletSendService.coinJoinSweepUserMessage(for: error)
diff --git a/DashWallet/Sources/UI/Payments/ScanQR/DWCaptureSessionManager.m b/DashWallet/Sources/UI/Payments/ScanQR/DWCaptureSessionManager.m
index acbecdf9b5..ba13804f88 100644
--- a/DashWallet/Sources/UI/Payments/ScanQR/DWCaptureSessionManager.m
+++ b/DashWallet/Sources/UI/Payments/ScanQR/DWCaptureSessionManager.m
@@ -26,10 +26,10 @@
 
 @interface DWCaptureSessionManager () <AVCaptureMetadataOutputObjectsDelegate, AVCaptureVideoDataOutputSampleBufferDelegate>
 
-@property (null_resettable, nonatomic, strong) AVCaptureSession *captureSession;
-@property (null_resettable, nonatomic, strong) dispatch_queue_t sessionQueue;
-@property (null_resettable, nonatomic, strong) dispatch_queue_t metadataQueue;
-@property (null_resettable, nonatomic, strong) dispatch_queue_t framesOutputQueue;
+@property (nullable, nonatomic, strong) AVCaptureSession *captureSession;
+@property (nullable, nonatomic, strong) dispatch_queue_t sessionQueue;
+@property (nullable, nonatomic, strong) dispatch_queue_t metadataQueue;
+@property (nullable, nonatomic, strong) dispatch_queue_t framesOutputQueue;
 @property (nonatomic, assign, getter=isCaptureSessionConfigured) BOOL captureSessionConfigured;
 @property (atomic, assign, getter=isActive) BOOL active;
 
@@ -62,20 +62,28 @@ - (void)startPreviewCompletion:(void (^)(void))completion {
     [NSObject cancelPreviousPerformRequestsWithTarget:self
                                              selector:@selector(stopPreviewInternal)
                                                object:nil];
-    [NSObject cancelPreviousPerformRequestsWithTarget:self
-                                             selector:@selector(tearDown)
-                                               object:nil];
 
     void (^doStartPreview)(void) = ^{
-#if !TARGET_OS_SIMULATOR
+        // Mark the session active before any setup/start work. A teardown
+        // already scheduled by an earlier `stopPreview` cannot be cancelled
+        // (`dispatch_after` has no cancel), so it reads this flag on main and
+        // bails instead — see `tearDown`.
+        self.active = YES;
         [self setupCaptureSessionIfNeeded];
-#endif /* TARGET_OS_SIMULATOR */
 
-        dispatch_async(self.sessionQueue, ^{
-            self.active = YES;
+        // Bind the queue and session once. `setupCaptureSessionIfNeeded` is a
+        // no-op when a session is already configured, so these can only be nil
+        // if the camera is unavailable (no capture device — simulator, or a
+        // device whose camera the system won't hand over).
+        dispatch_queue_t queue = self.sessionQueue;
+        AVCaptureSession *session = self.captureSession;
+        if (!queue || !session) {
+            return;
+        }
 
-            if (!self.captureSession.isRunning) {
-                [self.captureSession startRunning];
+        dispatch_async(queue, ^{
+            if (!session.isRunning) {
+                [session startRunning];
             }
 
             dispatch_async(dispatch_get_main_queue(), ^{
@@ -123,8 +131,14 @@ - (void)switchTorch {
         return;
     }
 
-    dispatch_async(self.sessionQueue, ^{
-        if (!self.captureSession.isRunning) {
+    dispatch_queue_t queue = self.sessionQueue;
+    AVCaptureSession *session = self.captureSession;
+    if (!queue || !session) {
+        return;
+    }
+
+    dispatch_async(queue, ^{
+        if (!session.isRunning) {
             return;
         }
 
@@ -175,15 +189,32 @@ - (void)captureOutput:(AVCaptureOutput *)output
 
 - (void)stopPreviewInternal {
     DWLog(@"DWCaptureSessionManager: Stopping preview...");
-    dispatch_async(self.sessionQueue, ^{
-        if (self.captureSession.isRunning) {
-            [self.captureSession stopRunning];
+    dispatch_queue_t queue = self.sessionQueue;
+    AVCaptureSession *session = self.captureSession;
+    if (!queue || !session) {
+        return;
+    }
 
-            dispatch_async(dispatch_get_main_queue(), ^{
-                DWLog(@"DWCaptureSessionManager: Preview has been stopped");
-                [self performSelector:@selector(tearDown) withObject:nil afterDelay:SESSION_KEEPALIVE];
-            });
+    dispatch_async(queue, ^{
+        if (session.isRunning) {
+            [session stopRunning];
         }
+
+        // The delayed teardown is scheduled back on MAIN, not on the session
+        // queue: `captureSession`, the three queues and `captureSessionConfigured`
+        // are only ever read/written from main (startPreview / stopPreview are
+        // both main-thread entry points), so keeping the state transition there
+        // is what makes it race-free. Tearing down on the session queue instead
+        // let `tearDown` nil `sessionQueue` while a concurrent `startPreview`
+        // on main had already passed the `isCaptureSessionConfigured` check —
+        // which then dispatched onto a NULL queue.
+        dispatch_async(dispatch_get_main_queue(), ^{
+            DWLog(@"DWCaptureSessionManager: Preview has been stopped");
+            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(SESSION_KEEPALIVE * NSEC_PER_SEC)),
+                           dispatch_get_main_queue(), ^{
+                               [self tearDown];
+                           });
+        });
     });
 }
 
@@ -191,6 +222,24 @@ - (void)setupCaptureSessionIfNeeded {
     if (self.isCaptureSessionConfigured) {
         return;
     }
+
+    // No capture device means no session to configure — the simulator, or a
+    // device that won't vend the camera. `+[AVCaptureDeviceInput
+    // deviceInputWithDevice:error:]` raises NSInvalidArgumentException on a nil
+    // device, so bail before anything is allocated and leave
+    // `captureSessionConfigured` NO. `startPreviewCompletion:` sees the nil
+    // session and no-ops; the scan screen renders without a preview instead of
+    // crashing. (This replaces the previous `#if !TARGET_OS_SIMULATOR` guard,
+    // which only covered the simulator case.)
+    if ([AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo] == nil) {
+        DWLog(@"DWCaptureSessionManager: no video capture device available");
+        return;
+    }
+
+    self.captureSession = [[AVCaptureSession alloc] init];
+    self.sessionQueue = dispatch_queue_create("DWQRScanViewModel.CaptureSession.queue", DISPATCH_QUEUE_SERIAL);
+    self.metadataQueue = dispatch_queue_create("DWQRScanViewModel.CaptureMetadataOutput.queue", DISPATCH_QUEUE_SERIAL);
+    self.framesOutputQueue = dispatch_queue_create("DWQRScanViewModel.VideoFramesOutput.queue", DISPATCH_QUEUE_SERIAL);
     self.captureSessionConfigured = YES;
 
     dispatch_async(self.sessionQueue, ^{
@@ -252,44 +301,42 @@ - (void)setupCaptureSessionIfNeeded {
     });
 }
 
+/// Releases the session and its queues. Runs on MAIN — the same thread as
+/// `startPreviewCompletion:` / `stopPreview`, so `active` and the session state
+/// below are never read and written concurrently.
 - (void)tearDown {
     DWLog(@"DWCaptureSessionManager: Tearing down...");
-    self.captureSession = nil;
-    self.sessionQueue = nil;
-    self.metadataQueue = nil;
-    self.framesOutputQueue = nil;
-    self.captureSessionConfigured = NO;
-}
 
-- (AVCaptureSession *)captureSession {
-    if (!_captureSession) {
-        _captureSession = [[AVCaptureSession alloc] init];
-    }
-
-    return _captureSession;
-}
-
-- (dispatch_queue_t)sessionQueue {
-    if (!_sessionQueue) {
-        _sessionQueue = dispatch_queue_create("DWQRScanViewModel.CaptureSession.queue", DISPATCH_QUEUE_SERIAL);
+    // The scanner was reopened inside the keepalive window; the live session is
+    // in use. `active` is set on main by `doStartPreview`, so this check cannot
+    // race the assignment.
+    if (self.active) {
+        return;
     }
 
-    return _sessionQueue;
-}
-
-- (dispatch_queue_t)metadataQueue {
-    if (!_metadataQueue) {
-        _metadataQueue = dispatch_queue_create("DWQRScanViewModel.CaptureMetadataOutput.queue", DISPATCH_QUEUE_SERIAL);
+    AVCaptureSession *session = self.captureSession;
+    if (session) {
+        [session beginConfiguration];
+        for (AVCaptureOutput *output in [session.outputs copy]) {
+            if ([output isKindOfClass:[AVCaptureMetadataOutput class]]) {
+                [(AVCaptureMetadataOutput *)output setMetadataObjectsDelegate:nil queue:NULL];
+            }
+            else if ([output isKindOfClass:[AVCaptureVideoDataOutput class]]) {
+                [(AVCaptureVideoDataOutput *)output setSampleBufferDelegate:nil queue:NULL];
+            }
+            [session removeOutput:output];
+        }
+        for (AVCaptureInput *input in [session.inputs copy]) {
+            [session removeInput:input];
+        }
+        [session commitConfiguration];
     }
 
-    return _metadataQueue;
-}
-
-- (dispatch_queue_t)framesOutputQueue {
-    if (!_framesOutputQueue) {
-        _framesOutputQueue = dispatch_queue_create("DWQRScanViewModel.VideoFramesOutput.queue", DISPATCH_QUEUE_SERIAL);
-    }
-    return _framesOutputQueue;
+    self.captureSession = nil;
+    self.sessionQueue = nil;
+    self.metadataQueue = nil;
+    self.framesOutputQueue = nil;
+    self.captureSessionConfigured = NO;
 }
 
 @end
diff --git a/DashWallet/Sources/UI/Uphold/Transfer/Model/UpholdAmountModel.swift b/DashWallet/Sources/UI/Uphold/Transfer/Model/UpholdAmountModel.swift
index f05a656347..d3962f5528 100644
--- a/DashWallet/Sources/UI/Uphold/Transfer/Model/UpholdAmountModel.swift
+++ b/DashWallet/Sources/UI/Uphold/Transfer/Model/UpholdAmountModel.swift
@@ -84,7 +84,8 @@ final class UpholdAmountModel: BaseAmountModel {
 
     private func createTransaction(for amount: String, feeWasDeductedFromAmount: Bool, otpToken: String?) {
         guard let receiveAddress = SwiftDashSDKReceiveAddressReader.receiveAddress() else {
-            fatalError("Address should exist")
+            state = .fail
+            return
         }
 
         state = .loading
@@ -110,7 +111,10 @@ final class UpholdAmountModel: BaseAmountModel {
 
                 let notSufficientFunds = tx.total.compare(card.available) == .orderedDescending
                 guard !notSufficientFunds else {
-                    let amountNumber = Decimal(string: amount)!
+                    guard let amountNumber = Decimal(string: amount) else {
+                        self.state = .fail
+                        return
+                    }
                     let correctedAmountNumber = amountNumber - tx.fee.decimalValue
                     let correctedAmount = String(describing: correctedAmountNumber)
 
diff --git a/DashWallet/Sources/UI/Views/BaseController/BaseViewController+NetworkReachability.swift b/DashWallet/Sources/UI/Views/BaseController/BaseViewController+NetworkReachability.swift
index 60665e6b23..09f687e1bc 100644
--- a/DashWallet/Sources/UI/Views/BaseController/BaseViewController+NetworkReachability.swift
+++ b/DashWallet/Sources/UI/Views/BaseController/BaseViewController+NetworkReachability.swift
@@ -50,7 +50,9 @@ extension NetworkReachabilityHandling {
     }
 
     public func stopNetworkMonitoring() {
-        NotificationCenter.default.removeObserver(reachabilityObserver!)
+        guard let observer = reachabilityObserver else { return }
+        NotificationCenter.default.removeObserver(observer)
+        reachabilityObserver = nil
     }
 
     private func updateNetworkStatus() {