dotnet · kubaflo · Apr 30, 2026 · Apr 16, 2026 · Apr 21, 2026 · Apr 22, 2026
diff --git a/src/Controls/tests/TestCases.HostApp/Issues/Issue34558.cs b/src/Controls/tests/TestCases.HostApp/Issues/Issue34558.cs
@@ -0,0 +1,62 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 34558, "[Windows] WebView renders blank when HybridWebView and WebView coexist in same app", PlatformAffected.UWP)]
+public partial class Issue34558 : ContentPage
+{
+	public Issue34558()
+	{
+		var hybridStatusLabel = new Label
+		{
+			AutomationId = "HybridStatusLabel",
+			Text = "Test passes if WebView shows content below without any exception",
+		};
+
+		// HybridWebView — initializing this creates a separate CoreWebView2Environment (without fix)
+		// that conflicts with the regular WebView's default environment.
+		var hybridWebView = new HybridWebView
+		{
+			AutomationId = "HybridWebViewControl",
+			HybridRoot = "hybridroot",
+			HeightRequest = 120,
+			HorizontalOptions = LayoutOptions.Fill,
+		};
+
+		var webView = new WebView
+		{
+			AutomationId = "RegularWebView",
+			HeightRequest = 150,
+			HorizontalOptions = LayoutOptions.Fill,
+			Source = new HtmlWebViewSource { Html = "<html><body><h1>WebView should load here</h1><p>If you see this, the WebView is working.</p></body></html>" },
+		};
+
+		// This label is added to the layout only after the WebView successfully navigates,
+		// so the UI test can wait for it to appear as proof the WebView rendered content.
+		var webViewNavigatedLabel = new Label
+		{
+			AutomationId = "WebViewNavigatedLabel",
+			Text = "WebView successfully navigated and rendered content!",
+		};
+
+		var layout = new VerticalStackLayout
+		{
+			Spacing = 10,
+			Padding = new Thickness(16),
+			Children =
+			{
+				hybridStatusLabel,
+				hybridWebView,
+				webView,
+			}
+		};
+
+		webView.Navigated += (s, e) =>
+		{
+			if (e.Result == WebNavigationResult.Success)
+			{
+				layout.Children.Add(webViewNavigatedLabel);
+			}
+		};
+
+		Content = layout;
+	}
+}
diff --git a/src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue34558.cs b/src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue34558.cs
@@ -0,0 +1,27 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue34558 : _IssuesUITest
+{
+	public Issue34558(TestDevice device) : base(device) { }
+
+	public override string Issue => "[Windows] WebView renders blank when HybridWebView and WebView coexist in same app";
+
+	[Test]
+	[Category(UITestCategories.WebView)]
+	public void WebViewLoadsWhenCoexistingWithHybridWebView()
+	{
+		App.WaitForElement("HybridStatusLabel");
+		App.WaitForElement("RegularWebView");
+
+		var rect = App.WaitForElement("RegularWebView").GetRect();
+		Assert.That(rect.Height, Is.GreaterThan(0), "WebView should render with non-zero height");
+
+		// "WebViewNavigatedLabel" is only added to the layout after the WebView successfully
+		// navigates. Waiting for it confirms the WebView rendered content and was not blank.
+		App.WaitForElement("WebViewNavigatedLabel");
+	}
+}
diff --git a/src/Core/src/Handlers/HybridWebView/HybridWebViewHandler.Windows.cs b/src/Core/src/Handlers/HybridWebView/HybridWebViewHandler.Windows.cs
@@ -307,17 +307,38 @@ private async Task<bool> TryInitializeWebView2(WebView2 webView)
 				var initializingArgs = new WebViewInitializationStartedEventArgs();
 				VirtualView?.WebViewInitializationStarted(initializingArgs);
 
-				var env = await CoreWebView2Environment.CreateWithOptionsAsync(
-					browserExecutableFolder: initializingArgs.BrowserExecutableFolder,
-					userDataFolder: initializingArgs.UserDataFolder,
-					options: initializingArgs.EnvironmentOptions);
+				// Only create a custom CoreWebView2Environment when the user has provided custom
+				// settings. Creating a separate environment with all-default settings conflicts with
+				// other WebView2 controls (e.g., regular WebView) in the same app that use the
+				// default environment, because WebView2 requires all controls sharing the same user
+				// data folder to use compatible environments. When no customizations are needed,
+				// use EnsureCoreWebView2Async() so this control joins the default shared environment.
+				bool hasCustomSettings =
+					initializingArgs.BrowserExecutableFolder != null ||
+					initializingArgs.UserDataFolder != null ||
+					initializingArgs.EnvironmentOptions != null ||
+					!string.IsNullOrEmpty(initializingArgs.ScriptLocale) ||
+					initializingArgs.IsInPrivateModeEnabled ||
+					!string.IsNullOrEmpty(initializingArgs.ProfileName);
+
+				if (hasCustomSettings)
+				{
+					var env = await CoreWebView2Environment.CreateWithOptionsAsync(
+						browserExecutableFolder: initializingArgs.BrowserExecutableFolder,
+						userDataFolder: initializingArgs.UserDataFolder,
+						options: initializingArgs.EnvironmentOptions);
 
-				var options = env.CreateCoreWebView2ControllerOptions();
-				options.ScriptLocale = initializingArgs.ScriptLocale;
-				options.IsInPrivateModeEnabled = initializingArgs.IsInPrivateModeEnabled;
-				options.ProfileName = initializingArgs.ProfileName;
+					var options = env.CreateCoreWebView2ControllerOptions();
+					options.ScriptLocale = initializingArgs.ScriptLocale;
+					options.IsInPrivateModeEnabled = initializingArgs.IsInPrivateModeEnabled;
+					options.ProfileName = initializingArgs.ProfileName;
 
-				await webView.EnsureCoreWebView2Async(env, options);
+					await webView.EnsureCoreWebView2Async(env, options);
+				}
+				else
+				{
+					await webView.EnsureCoreWebView2Async();
+				}
 
 				webView.CoreWebView2.Settings.AreDevToolsEnabled = Handler?.DeveloperTools.Enabled ?? false;
 				webView.CoreWebView2.Settings.IsWebMessageEnabled = true;