Visual studio 2017 Designer Crash

[PlPt]

Description
Visual Studio 2017 Designer Crashes everytime when open a WinForms which contains WebView2 Control.

The error message seems like there is a DLL not Found, but which DLL? It's not clear which DLLs VisualStudio needs at DesignTime. Compile and run this code works perfectly.
In ProcessMonitor i had no chance to identify which DLL is should be.
If I Remove all WebView2 Element from my project and add it again, it works for a week or two.
But then I have to remove it again. It's frustrating since it needs hours to do...

In Event Log there is following Message:
Anwendung: devenv.exe
Frameworkversion: v4.0.30319
Beschreibung: Der Prozess wurde aufgrund einer unbehandelten Ausnahme beendet.
Ausnahmeinformationen: System.DllNotFoundException
bei Microsoft.Web.WebView2.Core.CoreWebView2Environment.CreateCoreWebView2EnvironmentWithOptions(System.String, System.String, Microsoft.Web.WebView2.Core.Raw.ICoreWebView2EnvironmentOptions, Microsoft.Web.WebView2.Core.Raw.ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler)
bei Microsoft.Web.WebView2.Core.CoreWebView2Environment+d__3.MoveNext()

Ausnahmeinformationen: System.AggregateException
bei System.Threading.Tasks.Task.WaitAll(System.Threading.Tasks.Task[], Int32, System.Threading.CancellationToken)
bei WebView2Test.WebView2Helper.InitializeWebView2Env()
bei WebView2Test.WebView2Helper+d__4.MoveNext()
bei System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.b__6_0(System.Object)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
bei System.Windows.Threading.DispatcherOperation.InvokeImpl()
bei System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(System.Object)
bei MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(System.Object)
bei System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
bei System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
bei System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
bei MS.Internal.CulturePreservingExecutionContext.Run(MS.Internal.CulturePreservingExecutionContext, System.Threading.ContextCallback, System.Object)
bei System.Windows.Threading.DispatcherOperation.Invoke()
bei System.Windows.Threading.Dispatcher.ProcessQueue()
bei System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
bei MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
bei System.Windows.Threading.Dispatcher.LegacyInvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)
bei MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)

Version
SDK: 1.0.705.50
Runtime: Microsoft.WebView2.FixedVersionRuntime.88.0.705.68.x64
Framework: WinForms based on .NET 5.6.1
OS: Win10 20H2

Repro Steps
Dont't know since it's not a problem in all project. It appears with no reason.

AB#44876576

[PlPt]

Update: If I deactivateWebView2 Initialise at Design Time it works like it should:

 if (Application.ExecutablePath.IndexOf("devenv.exe", StringComparison.OrdinalIgnoreCase) > -1)
      {
      //Design time, no init due to DllNotFound Exception of VisualStudio
      }
      else
      {
        await webView.EnsureCoreWebView2Async(environment);
      }

The strange thing is: I dont call Core init at Design time. That must be the designer itsself..

[champnic]

Pascal Petzoldt (@PlPt) Thanks for the bug report Pascal! I've added this to our backlog.

We do have some code that blocks initialization when in designer but maybe that's not working in this case.

[cartermq]

Pascal Petzoldt (@PlPt) You are a gentleman and a scholar thanks for the work around a huge help for me.

[jelenv]

I have encountered similar or same issue. In Visual Studio 2022 and 2019 versions. Everytime I have somewhere in WinForm code:
await webView.EnsureCoreWebView2Async(null);, then the designer crashes during opening. Weird thing is, it crashes only on opening one Form design in the solution, and the other ones are fine (even when they use webView too).

[DocMoebiuz]

I have encountered similar or same issue. In Visual Studio 2022 and 2019 versions. Everytime I have somewhere in WinForm code: await webView.EnsureCoreWebView2Async(null);, then the designer crashes during opening. Weird thing is, it crashes only on opening one Form design in the solution, and the other ones are fine (even when they use webView too).

I am experiencing the same issue. My main form contains the UserControl which contains the WebView. The User Control calls webView.EnsureCoreWebView2Async - as soon as this user control is on the main form, VS2022 crashes every time I want to open the Designer View for the main view,

[champnic]

The behavior of the WebView2 control when in Designer is to not actually load anything, and instead show a gray box with black text saying "WebView2". Calling EnsureCoreWebView2Async is similarly short-circuited and becomes a no-op. If your code is assuming the WebView2 exists and is interactable while in design mode (ie. that WebView2.CoreWebView2 is available and valid), then it could fail.

You can try to workaround this by avoiding calling into the WebView2 or expecting it to be valid when DesignerProperties.GetIsInDesignMode(this) == true.

[Atlandics]

这都好几年了这个bug还在呢，啥时候能修复啊，还是说不修了？