diff --git a/code/lib/core-server/src/build-dev.ts b/code/lib/core-server/src/build-dev.ts
index ef3d7e3cc3f8..7d1a223e1703 100644
--- a/code/lib/core-server/src/build-dev.ts
+++ b/code/lib/core-server/src/build-dev.ts
@@ -14,6 +14,7 @@ import {
   validateFrameworkName,
 } from '@storybook/core-common';
 import prompts from 'prompts';
+import invariant from 'tiny-invariant';
 import { global } from '@storybook/global';
 import { telemetry } from '@storybook/telemetry';
 
@@ -31,7 +32,7 @@ export async function buildDevStandalone(
 ): Promise<{ port: number; address: string; networkAddress: string }> {
   const { packageJson, versionUpdates } = options;
   const { version } = packageJson;
-
+  invariant(version !== undefined, 'Expected package.json version to be defined.');
   // updateInfo are cached, so this is typically pretty fast
   const [port, versionCheck] = await Promise.all([
     getServerPort(options.port),
@@ -63,9 +64,10 @@ export async function buildDevStandalone(
 
   const config = await loadMainConfig(options);
   const { framework } = config;
+  invariant(framework, 'framework is required in Storybook v7');
   const corePresets = [];
 
-  const frameworkName = typeof framework === 'string' ? framework : framework?.name;
+  const frameworkName = typeof framework === 'string' ? framework : framework.name;
   validateFrameworkName(frameworkName);
 
   corePresets.push(join(frameworkName, 'preset'));
@@ -82,6 +84,7 @@ export async function buildDevStandalone(
   });
 
   const { renderer, builder, disableTelemetry } = await presets.apply<CoreConfig>('core', {});
+  invariant(builder, 'no builder configured!');
 
   if (!options.disableTelemetry && !disableTelemetry) {
     if (versionCheck.success && !versionCheck.cached) {
@@ -89,23 +92,26 @@ export async function buildDevStandalone(
     }
   }
 
-  const builderName = typeof builder === 'string' ? builder : builder?.name;
+  const builderName = typeof builder === 'string' ? builder : builder.name;
   const [previewBuilder, managerBuilder] = await Promise.all([
     getPreviewBuilder(builderName, options.configDir),
     getManagerBuilder(),
   ]);
 
+  const resolvedRenderer = renderer
+    ? resolveAddonName(options.configDir, renderer, options)
+    : undefined;
   // Load second pass: all presets are applied in order
   presets = await loadAllPresets({
     corePresets: [
       require.resolve('@storybook/core-server/dist/presets/common-preset'),
       ...(managerBuilder.corePresets || []),
       ...(previewBuilder.corePresets || []),
-      ...(renderer ? [resolveAddonName(options.configDir, renderer, options)] : []),
+      ...(resolvedRenderer ? [resolvedRenderer] : []),
       ...corePresets,
       require.resolve('@storybook/core-server/dist/presets/babel-cache-preset'),
     ],
-    overridePresets: previewBuilder.overridePresets,
+    overridePresets: previewBuilder.overridePresets ?? [],
     ...options,
   });
 
@@ -123,8 +129,7 @@ export async function buildDevStandalone(
   );
 
   const previewTotalTime = previewResult && previewResult.totalTime;
-  const managerTotalTime = managerResult && managerResult.totalTime;
-
+  const managerTotalTime = managerResult ? managerResult.totalTime : undefined;
   const previewStats = previewResult && previewResult.stats;
   const managerStats = managerResult && managerResult.stats;
 
diff --git a/code/lib/core-server/src/build-static.ts b/code/lib/core-server/src/build-static.ts
index 8bbfff506316..6682046662aa 100644
--- a/code/lib/core-server/src/build-static.ts
+++ b/code/lib/core-server/src/build-static.ts
@@ -91,13 +91,15 @@ export async function buildStaticStandalone(options: BuildStaticStandaloneOption
 
   const [previewBuilder, managerBuilder] = await getBuilders({ ...options, presets });
   const { renderer } = await presets.apply<CoreConfig>('core', {});
-
+  const resolvedRenderer = renderer
+    ? resolveAddonName(options.configDir, renderer, options)
+    : undefined;
   presets = await loadAllPresets({
     corePresets: [
       require.resolve('@storybook/core-server/dist/presets/common-preset'),
       ...(managerBuilder.corePresets || []),
       ...(previewBuilder.corePresets || []),
-      ...(renderer ? [resolveAddonName(options.configDir, renderer, options)] : []),
+      ...(resolvedRenderer ? [resolvedRenderer] : []),
       ...corePresets,
       require.resolve('@storybook/core-server/dist/presets/babel-cache-preset'),
     ],
@@ -151,7 +153,8 @@ export async function buildStaticStandalone(options: BuildStaticStandaloneOption
   );
   effects.push(copy(coreServerPublicDir, options.outputDir));
 
-  let initializedStoryIndexGenerator: Promise<StoryIndexGenerator> = Promise.resolve(undefined);
+  let initializedStoryIndexGenerator: Promise<StoryIndexGenerator | undefined> =
+    Promise.resolve(undefined);
   if ((features?.buildStoriesJson || features?.storyStoreV7) && !options.ignorePreview) {
     const workingDir = process.cwd();
     const directories = {
@@ -167,17 +170,21 @@ export async function buildStaticStandalone(options: BuildStaticStandaloneOption
       storyStoreV7: !!features?.storyStoreV7,
     });
 
-    initializedStoryIndexGenerator = generator.initialize().then(() => generator);
+    const initializedStoryIndexGeneratorPromise = generator.initialize().then(() => generator);
     effects.push(
       extractStoriesJson(
         join(options.outputDir, 'stories.json'),
-        initializedStoryIndexGenerator,
+        initializedStoryIndexGeneratorPromise,
         convertToIndexV3
       )
     );
     effects.push(
-      extractStoriesJson(join(options.outputDir, 'index.json'), initializedStoryIndexGenerator)
+      extractStoriesJson(
+        join(options.outputDir, 'index.json'),
+        initializedStoryIndexGeneratorPromise
+      )
     );
+    initializedStoryIndexGenerator = initializedStoryIndexGeneratorPromise;
   }
 
   if (!core?.disableProjectJson) {
diff --git a/code/lib/core-server/src/dev-server.ts b/code/lib/core-server/src/dev-server.ts
index 6843c194e180..2eb1ea420cda 100644
--- a/code/lib/core-server/src/dev-server.ts
+++ b/code/lib/core-server/src/dev-server.ts
@@ -1,5 +1,6 @@
 import express from 'express';
 import compression from 'compression';
+import invariant from 'tiny-invariant';
 
 import type { CoreConfig, Options, StorybookConfig } from '@storybook/types';
 
@@ -34,16 +35,13 @@ export async function storybookDevServer(options: Options) {
     getServerChannel(server)
   );
 
-  let indexError: Error;
+  let indexError: Error | undefined;
   // try get index generator, if failed, send telemetry without storyCount, then rethrow the error
-  const initializedStoryIndexGenerator: Promise<StoryIndexGenerator> = getStoryIndexGenerator(
-    features,
-    options,
-    serverChannel
-  ).catch((err) => {
-    indexError = err;
-    return undefined;
-  });
+  const initializedStoryIndexGenerator: Promise<StoryIndexGenerator | undefined> =
+    getStoryIndexGenerator(features ?? {}, options, serverChannel).catch((err) => {
+      indexError = err;
+      return undefined;
+    });
 
   app.use(compression({ level: 1 }));
 
@@ -51,7 +49,7 @@ export async function storybookDevServer(options: Options) {
     options.extendServer(server);
   }
 
-  app.use(getAccessControlMiddleware(core?.crossOriginIsolated));
+  app.use(getAccessControlMiddleware(core?.crossOriginIsolated ?? false));
   app.use(getCachingMiddleware());
 
   getMiddleware(options.configDir)(router);
@@ -59,6 +57,7 @@ export async function storybookDevServer(options: Options) {
   app.use(router);
 
   const { port, host, initialPath } = options;
+  invariant(port, 'expected options to have a port');
   const proto = options.https ? 'https' : 'http';
   const { address, networkAddress } = getServerAddresses(port, host, proto, initialPath);
 
@@ -67,6 +66,7 @@ export async function storybookDevServer(options: Options) {
     server.listen({ port, host }, (error: Error) => (error ? reject(error) : resolve()));
   });
 
+  invariant(core?.builder, 'no builder configured!');
   const builderName = typeof core?.builder === 'string' ? core.builder : core?.builder?.name;
 
   const [previewBuilder, managerBuilder] = await Promise.all([
diff --git a/code/lib/core-server/src/presets/common-preset.ts b/code/lib/core-server/src/presets/common-preset.ts
index 800f7ccaf0f7..76240e469f4e 100644
--- a/code/lib/core-server/src/presets/common-preset.ts
+++ b/code/lib/core-server/src/presets/common-preset.ts
@@ -44,7 +44,7 @@ export const staticDirs: PresetPropertyFn<'staticDirs'> = async (values = []) =>
 ];
 
 export const favicon = async (
-  value: string,
+  value: string | undefined,
   options: Pick<Options, 'presets' | 'configDir' | 'staticDir'>
 ) => {
   if (value) {
@@ -257,8 +257,13 @@ type WhatsNewResponse = {
   excerpt: string;
 };
 
+type OptionsWithRequiredCache = Exclude<Options, 'cache'> & Required<Pick<Options, 'cache'>>;
+
 // eslint-disable-next-line @typescript-eslint/naming-convention
-export const experimental_serverChannel = async (channel: Channel, options: Options) => {
+export const experimental_serverChannel = async (
+  channel: Channel,
+  options: OptionsWithRequiredCache
+) => {
   const coreOptions = await options.presets.apply('core');
 
   channel.on(SET_WHATS_NEW_CACHE, async (data: WhatsNewCache) => {
@@ -277,7 +282,10 @@ export const experimental_serverChannel = async (channel: Channel, options: Opti
         throw response;
       })) as WhatsNewResponse;
 
-      const main = await readConfig(findConfigFile('main', options.configDir));
+      const configFileName = findConfigFile('main', options.configDir);
+      if (!configFileName)
+        throw new Error(`unable to find storybook main file in ${options.configDir}`);
+      const main = await readConfig(configFileName);
       const disableWhatsNewNotifications = main.getFieldValue([
         'core',
         'disableWhatsNewNotifications',
@@ -293,7 +301,7 @@ export const experimental_serverChannel = async (channel: Channel, options: Opti
       } satisfies WhatsNewData;
       channel.emit(RESULT_WHATS_NEW_DATA, { data });
     } catch (e) {
-      logger.verbose(e);
+      logger.verbose(e instanceof Error ? e.message : String(e));
       channel.emit(RESULT_WHATS_NEW_DATA, {
         data: { status: 'ERROR' } satisfies WhatsNewData,
       });
@@ -305,7 +313,10 @@ export const experimental_serverChannel = async (channel: Channel, options: Opti
     async ({ disableWhatsNewNotifications }: { disableWhatsNewNotifications: boolean }) => {
       const isTelemetryEnabled = coreOptions.disableTelemetry !== true;
       try {
-        const main = await readConfig(findConfigFile('main', options.configDir));
+        const configFileName = findConfigFile('main', options.configDir);
+        if (!configFileName)
+          throw new Error(`unable to find storybook main file in ${options.configDir}`);
+        const main = await readConfig(configFileName);
         main.setFieldValue(['core', 'disableWhatsNewNotifications'], disableWhatsNewNotifications);
         await writeConfig(main);
 
@@ -314,7 +325,7 @@ export const experimental_serverChannel = async (channel: Channel, options: Opti
         }
       } catch (error) {
         if (isTelemetryEnabled) {
-          await sendTelemetryError(error, 'core-config', {
+          await sendTelemetryError(error as Error, 'core-config', {
             cliOptions: options,
             presetOptions: { ...options, corePresets: [], overridePresets: [] },
             skipPrompt: true,
diff --git a/code/lib/core-server/src/standalone.ts b/code/lib/core-server/src/standalone.ts
index 392f9027a000..bef85d55023d 100644
--- a/code/lib/core-server/src/standalone.ts
+++ b/code/lib/core-server/src/standalone.ts
@@ -4,7 +4,7 @@ import { buildDevStandalone } from './build-dev';
 
 async function build(options: any = {}, frameworkOptions: any = {}) {
   const { mode = 'dev' } = options;
-  const { packageJson } = readUpSync({ cwd: __dirname });
+  const packageJson = readUpSync({ cwd: __dirname })?.packageJson;
 
   const commonOptions = {
     ...options,
diff --git a/code/lib/core-server/src/utils/StoryIndexGenerator.ts b/code/lib/core-server/src/utils/StoryIndexGenerator.ts
index 221fa7665189..cceef09459fc 100644
--- a/code/lib/core-server/src/utils/StoryIndexGenerator.ts
+++ b/code/lib/core-server/src/utils/StoryIndexGenerator.ts
@@ -94,10 +94,10 @@ export class StoryIndexGenerator {
   // Cache the last value of `getStoryIndex`. We invalidate (by unsetting) when:
   //  - any file changes, including deletions
   //  - the preview changes [not yet implemented]
-  private lastIndex?: StoryIndex;
+  private lastIndex?: StoryIndex | null;
 
   // Same as the above but for the error case
-  private lastError?: Error;
+  private lastError?: Error | null;
 
   constructor(
     public readonly specifiers: NormalizedStoriesSpecifier[],
@@ -171,6 +171,10 @@ export class StoryIndexGenerator {
     await Promise.all(
       this.specifiers.map(async (specifier) => {
         const entry = this.specifierToCache.get(specifier);
+        if (!entry)
+          throw new Error(
+            `specifier ${specifier} does not have a matching cache entry in specifierToCache`
+          );
         return Promise.all(
           Object.keys(entry).map(async (absolutePath) => {
             if (entry[absolutePath] && !overwrite) return;
@@ -185,7 +189,11 @@ export class StoryIndexGenerator {
 
               entry[absolutePath] = {
                 type: 'error',
-                err: new IndexingError(err.message, [relativePath], err.stack),
+                err: new IndexingError(
+                  err instanceof Error ? err.message : String(err),
+                  [relativePath],
+                  err instanceof Error ? err.stack : undefined
+                ),
               };
             }
           })
@@ -213,6 +221,10 @@ export class StoryIndexGenerator {
 
     return this.specifiers.flatMap((specifier) => {
       const cache = this.specifierToCache.get(specifier);
+      if (!cache)
+        throw new Error(
+          `specifier ${specifier} does not have a matching cache entry in specifierToCache`
+        );
       return Object.values(cache).flatMap((entry): (IndexEntry | ErrorEntry)[] => {
         if (!entry) return [];
         if (entry.type === 'docs') return [entry];
@@ -245,7 +257,12 @@ export class StoryIndexGenerator {
     const entries = [] as IndexEntry[];
     const importPath = slash(normalizeStoryPath(relativePath));
     const makeTitle = (userTitle?: string) => {
-      return userOrAutoTitleFromSpecifier(importPath, specifier, userTitle);
+      const title = userOrAutoTitleFromSpecifier(importPath, specifier, userTitle);
+      if (!title)
+        throw new Error(
+          "makeTitle created an undefined title. This happens when a specifier's doesn't have any matches in its fileName"
+        );
+      return title;
     };
 
     const storyIndexer = this.options.storyIndexers.find((indexer) =>
@@ -255,11 +272,11 @@ export class StoryIndexGenerator {
       throw new Error(`No matching story indexer found for ${absolutePath}`);
     }
     const csf = await storyIndexer.indexer(absolutePath, { makeTitle });
-
     const componentTags = csf.meta.tags || [];
     csf.stories.forEach(({ id, name, tags: storyTags, parameters }) => {
       if (!parameters?.docsOnly) {
         const tags = [...(storyTags || componentTags), 'story'];
+        invariant(csf.meta.title);
         entries.push({ id, title: csf.meta.title, name, importPath, tags, type: 'story' });
       }
     });
@@ -273,6 +290,8 @@ export class StoryIndexGenerator {
       //  b) we have docs page enabled for this file
       if (componentTags.includes(STORIES_MDX_TAG) || autodocsOptedIn) {
         const name = this.options.docs.defaultName;
+        if (!name) throw new Error('expected a defaultName property in options.docs');
+        invariant(csf.meta.title);
         const id = toId(csf.meta.title, name);
         entries.unshift({
           id,
@@ -332,7 +351,7 @@ export class StoryIndexGenerator {
 
       // Also, if `result.of` is set, it means that we're using the `<Meta of={XStories} />` syntax,
       // so find the `title` defined the file that `meta` points to.
-      let csfEntry: StoryIndexEntry;
+      let csfEntry: StoryIndexEntry | undefined;
       if (result.of) {
         const absoluteOf = makeAbsolute(result.of, normalizedPath, this.options.workingDir);
         dependencies.forEach((dep) => {
@@ -369,7 +388,13 @@ export class StoryIndexGenerator {
 
       const title =
         csfEntry?.title || userOrAutoTitleFromSpecifier(importPath, specifier, result.title);
+      if (!title)
+        throw new Error(
+          "makeTitle created an undefined title. This happens when a specifier's doesn't have any matches in its fileName"
+        );
       const { defaultName } = this.options.docs;
+      if (!defaultName) throw new Error('expected a defaultName property in options.docs');
+
       const name =
         result.name ||
         (csfEntry ? autoName(importPath, csfEntry.importPath, defaultName) : defaultName);
@@ -386,7 +411,7 @@ export class StoryIndexGenerator {
       };
       return docsEntry;
     } catch (err) {
-      if (err.source?.match(/mdast-util-mdx-jsx/g)) {
+      if (err && (err as { source: any }).source?.match(/mdast-util-mdx-jsx/g)) {
         logger.warn(
           `💡 This seems to be an MDX2 syntax error. Please refer to the MDX section in the following resource for assistance on how to fix this: ${chalk.yellow(
             'https://storybook.js.org/migration-guides/7.0'
@@ -512,7 +537,7 @@ export class StoryIndexGenerator {
             indexEntries[entry.id] = entry;
           }
         } catch (err) {
-          duplicateErrors.push(err);
+          if (err instanceof IndexingError) duplicateErrors.push(err);
         }
       });
       if (duplicateErrors.length) throw new MultipleIndexingError(duplicateErrors);
@@ -552,9 +577,9 @@ export class StoryIndexGenerator {
 
       return this.lastIndex;
     } catch (err) {
-      this.lastError = err;
-      logger.warn(`🚨 ${this.lastError.toString()}`);
+      this.lastError = err == null || err instanceof Error ? err : undefined;
       invariant(this.lastError);
+      logger.warn(`🚨 ${this.lastError.toString()}`);
       throw this.lastError;
     }
   }
@@ -562,7 +587,7 @@ export class StoryIndexGenerator {
   invalidate(specifier: NormalizedStoriesSpecifier, importPath: Path, removed: boolean) {
     const absolutePath = slash(path.resolve(this.options.workingDir, importPath));
     const cache = this.specifierToCache.get(specifier);
-
+    if (!cache) throw new Error(`no `);
     const cacheEntry = cache[absolutePath];
     if (cacheEntry && cacheEntry.type === 'stories') {
       const { dependents } = cacheEntry;
diff --git a/code/lib/core-server/src/utils/copy-all-static-files.ts b/code/lib/core-server/src/utils/copy-all-static-files.ts
index 2e6475acc8c2..44f7bf12d31f 100644
--- a/code/lib/core-server/src/utils/copy-all-static-files.ts
+++ b/code/lib/core-server/src/utils/copy-all-static-files.ts
@@ -22,7 +22,7 @@ export async function copyAllStaticFiles(staticDirs: any[] | undefined, outputDi
             filter: (_, dest) => !skipPaths.includes(dest),
           });
         } catch (e) {
-          logger.error(e.message);
+          if (e instanceof Error) logger.error(e.message);
           process.exit(-1);
         }
       })
@@ -37,7 +37,7 @@ export async function copyAllStaticFilesRelativeToMain(
 ) {
   const workingDir = process.cwd();
 
-  return staticDirs.reduce(async (acc, dir) => {
+  return staticDirs?.reduce(async (acc, dir) => {
     await acc;
 
     const staticDirAndTarget = typeof dir === 'string' ? dir : `${dir.from}:${dir.to}`;
diff --git a/code/lib/core-server/src/utils/doTelemetry.ts b/code/lib/core-server/src/utils/doTelemetry.ts
index 1a5b62d6ce92..ecb494fc45f5 100644
--- a/code/lib/core-server/src/utils/doTelemetry.ts
+++ b/code/lib/core-server/src/utils/doTelemetry.ts
@@ -1,3 +1,4 @@
+import invariant from 'tiny-invariant';
 import type { CoreConfig, Options, StoryIndex } from '@storybook/types';
 import { telemetry, getPrecedingUpgrade } from '@storybook/telemetry';
 import { useStorybookMetadata } from './metadata';
@@ -9,17 +10,18 @@ import { sendTelemetryError } from '../withTelemetry';
 
 export async function doTelemetry(
   core: CoreConfig,
-  initializedStoryIndexGenerator: Promise<StoryIndexGenerator>,
+  initializedStoryIndexGenerator: Promise<StoryIndexGenerator | undefined>,
   options: Options
 ) {
   if (!core?.disableTelemetry) {
     initializedStoryIndexGenerator.then(async (generator) => {
-      let storyIndex: StoryIndex;
+      let storyIndex: StoryIndex | undefined;
       try {
         storyIndex = await generator?.getIndex();
       } catch (err) {
         // If we fail to get the index, treat it as a recoverable error, but send it up to telemetry
         // as if we crashed. In the future we will revisit this to send a distinct error
+        if (!(err instanceof Error)) throw new Error('encountered a non-recoverable error');
         sendTelemetryError(err, 'dev', {
           cliOptions: options,
           presetOptions: { ...options, corePresets: [], overridePresets: [] },
@@ -27,12 +29,16 @@ export async function doTelemetry(
         return;
       }
       const { versionCheck, versionUpdates } = options;
+      invariant(
+        !versionUpdates || (versionUpdates && versionCheck),
+        'versionCheck should be defined when versionUpdates is true'
+      );
       const payload = {
         precedingUpgrade: await getPrecedingUpgrade(),
       };
       if (storyIndex) {
         Object.assign(payload, {
-          versionStatus: versionUpdates ? versionStatus(versionCheck) : 'disabled',
+          versionStatus: versionUpdates && versionCheck ? versionStatus(versionCheck) : 'disabled',
           storyIndex: summarizeIndex(storyIndex),
         });
       }
diff --git a/code/lib/core-server/src/utils/get-builders.ts b/code/lib/core-server/src/utils/get-builders.ts
index 1b43381c02cc..7ed83e293613 100644
--- a/code/lib/core-server/src/utils/get-builders.ts
+++ b/code/lib/core-server/src/utils/get-builders.ts
@@ -1,5 +1,6 @@
 import type { Builder, CoreConfig, Options } from '@storybook/types';
 import { pathToFileURL } from 'node:url';
+import invariant from 'tiny-invariant';
 
 export async function getManagerBuilder(): Promise<Builder<unknown>> {
   return import('@storybook/builder-manager');
@@ -24,7 +25,8 @@ export async function getPreviewBuilder(
 
 export async function getBuilders({ presets, configDir }: Options): Promise<Builder<unknown>[]> {
   const { builder } = await presets.apply<CoreConfig>('core', {});
-  const builderName = typeof builder === 'string' ? builder : builder?.name;
+  invariant(builder, 'no builder configured!');
+  const builderName = typeof builder === 'string' ? builder : builder.name;
 
   return Promise.all([getPreviewBuilder(builderName, configDir), getManagerBuilder()]);
 }
diff --git a/code/lib/core-server/src/utils/get-server-channel.ts b/code/lib/core-server/src/utils/get-server-channel.ts
index f43f0dcf5b0e..c44c51b36307 100644
--- a/code/lib/core-server/src/utils/get-server-channel.ts
+++ b/code/lib/core-server/src/utils/get-server-channel.ts
@@ -3,7 +3,7 @@ import { isJSON, parse, stringify } from 'telejson';
 import type { ChannelHandler } from '@storybook/channels';
 import { Channel } from '@storybook/channels';
 
-type Server = ConstructorParameters<typeof WebSocketServer>[0]['server'];
+type Server = NonNullable<NonNullable<ConstructorParameters<typeof WebSocketServer>[0]>['server']>;
 
 /**
  * This class represents a channel transport that allows for a one-to-many relationship between the server and clients.
@@ -28,7 +28,7 @@ export class ServerChannelTransport {
       wss.on('message', (raw) => {
         const data = raw.toString();
         const event = typeof data === 'string' && isJSON(data) ? parse(data) : data;
-        this.handler(event);
+        this.handler?.(event);
       });
     });
   }
diff --git a/code/lib/core-server/src/utils/getStoryIndexGenerator.ts b/code/lib/core-server/src/utils/getStoryIndexGenerator.ts
index c1f75831806c..f7de41266822 100644
--- a/code/lib/core-server/src/utils/getStoryIndexGenerator.ts
+++ b/code/lib/core-server/src/utils/getStoryIndexGenerator.ts
@@ -15,7 +15,6 @@ export async function getStoryIndexGenerator(
   options: Options,
   serverChannel: ServerChannel
 ) {
-  let initializedStoryIndexGenerator: Promise<StoryIndexGenerator> = Promise.resolve(undefined);
   if (features?.buildStoriesJson || features?.storyStoreV7) {
     const workingDir = process.cwd();
     const directories = {
@@ -33,10 +32,10 @@ export async function getStoryIndexGenerator(
       docs: await docsOptions,
       workingDir,
       storiesV2Compatibility: !features?.storyStoreV7,
-      storyStoreV7: features?.storyStoreV7,
+      storyStoreV7: features.storyStoreV7 ?? false,
     });
 
-    initializedStoryIndexGenerator = generator.initialize().then(() => generator);
+    const initializedStoryIndexGenerator = generator.initialize().then(() => generator);
 
     useStoriesJson({
       router,
@@ -45,6 +44,8 @@ export async function getStoryIndexGenerator(
       serverChannel,
       workingDir,
     });
+
+    return initializedStoryIndexGenerator;
   }
-  return initializedStoryIndexGenerator;
+  return Promise.resolve(undefined);
 }
diff --git a/code/lib/core-server/src/utils/server-address.ts b/code/lib/core-server/src/utils/server-address.ts
index 3332fa53b0d3..5e4ae1b18b72 100644
--- a/code/lib/core-server/src/utils/server-address.ts
+++ b/code/lib/core-server/src/utils/server-address.ts
@@ -5,7 +5,7 @@ import detectFreePort from 'detect-port';
 
 export function getServerAddresses(
   port: number,
-  host: string,
+  host: string | undefined,
   proto: string,
   initialPath?: string
 ) {
@@ -26,7 +26,7 @@ export function getServerAddresses(
   };
 }
 
-export const getServerPort = (port: number) =>
+export const getServerPort = (port?: number) =>
   detectFreePort(port).catch((error) => {
     logger.error(error);
     process.exit(-1);
diff --git a/code/lib/core-server/src/utils/server-statics.ts b/code/lib/core-server/src/utils/server-statics.ts
index 96386df1d05a..a5ccc59fbd21 100644
--- a/code/lib/core-server/src/utils/server-statics.ts
+++ b/code/lib/core-server/src/utils/server-statics.ts
@@ -26,7 +26,7 @@ export async function useStatics(router: any, options: Options) {
   }
 
   const statics = [
-    ...staticDirs.map((dir) => (typeof dir === 'string' ? dir : `${dir.from}:${dir.to}`)),
+    ...(staticDirs ?? []).map((dir) => (typeof dir === 'string' ? dir : `${dir.from}:${dir.to}`)),
     ...(options.staticDir || []),
   ];
 
@@ -52,7 +52,7 @@ export async function useStatics(router: any, options: Options) {
 
           router.use(targetEndpoint, express.static(staticPath, { index: false }));
         } catch (e) {
-          logger.warn(e.message);
+          if (e instanceof Error) logger.warn(e.message);
         }
       })
     );
diff --git a/code/lib/core-server/src/utils/stories-json.ts b/code/lib/core-server/src/utils/stories-json.ts
index 6ab44e1dcf5b..7070245a6043 100644
--- a/code/lib/core-server/src/utils/stories-json.ts
+++ b/code/lib/core-server/src/utils/stories-json.ts
@@ -51,7 +51,7 @@ export function useStoriesJson({
       res.send(JSON.stringify(index));
     } catch (err) {
       res.status(500);
-      res.send(err.toString());
+      res.send(err instanceof Error ? err.toString() : String(err));
     }
   });
 
@@ -63,7 +63,7 @@ export function useStoriesJson({
       res.send(JSON.stringify(index));
     } catch (err) {
       res.status(500);
-      res.send(err.toString());
+      res.send(err instanceof Error ? err.toString() : String(err));
     }
   });
 }
diff --git a/code/lib/core-server/src/withTelemetry.ts b/code/lib/core-server/src/withTelemetry.ts
index 82bd7488dd21..1888f733cd04 100644
--- a/code/lib/core-server/src/withTelemetry.ts
+++ b/code/lib/core-server/src/withTelemetry.ts
@@ -42,11 +42,7 @@ async function getErrorLevel({
   if (!presetOptions) return 'full';
 
   // should we load the preset?
-  const presets = await loadAllPresets({
-    corePresets: [require.resolve('@storybook/core-server/dist/presets/common-preset')],
-    overridePresets: [],
-    ...presetOptions,
-  });
+  const presets = await loadAllPresets(presetOptions);
 
   // If the user has chosen to enable/disable crash reports in main.js
   // or disabled telemetry, we can return that
@@ -108,7 +104,7 @@ export async function withTelemetry<T>(
   eventType: EventType,
   options: TelemetryOptions,
   run: () => Promise<T>
-): Promise<T> {
+): Promise<T | undefined> {
   let canceled = false;
 
   async function cancelTelemetry() {
@@ -136,8 +132,8 @@ export async function withTelemetry<T>(
     }
 
     const { printError = logger.error } = options;
-    printError(error);
-    await sendTelemetryError(error, eventType, options);
+    printError(error instanceof Error ? error.message : String(error));
+    if (error instanceof Error) await sendTelemetryError(error, eventType, options);
 
     throw error;
   } finally {
diff --git a/code/lib/core-server/tsconfig.json b/code/lib/core-server/tsconfig.json
index a6f65038a17b..1dc5a72190bd 100644
--- a/code/lib/core-server/tsconfig.json
+++ b/code/lib/core-server/tsconfig.json
@@ -2,7 +2,7 @@
   "extends": "../../tsconfig.json",
   "compilerOptions": {
     "skipLibCheck": true,
-    "strict": false
+    "strict": true
   },
   "include": ["src/**/*"]
 }