Unable to cast object of type 'System.Object' to type 'InstantiateToolWindowData'.

[meadisu27]

Frequently receive the following error when debugging VSIX. Only resolution is to reset the experimental instance. However, it then occurs after some unknown circumstances.

System.InvalidCastException: Unable to cast object of type 'System.Object' to type 'InstantiateToolWindowData'.
   at Community.VisualStudio.Toolkit.ToolkitPackage.InstantiateToolWindow(Type toolWindowType, Object context)
   at Microsoft.VisualStudio.Shell.Package.<>c__DisplayClass84_0.<CreateToolWindow>g__CreateToolWindowWorker|1()
   at Microsoft.VisualStudio.Shell.Package.CreateToolWindow(Type toolWindowType, Int32 id, UInt32 flags, Object context, Guid persistenceGuid)
   at Microsoft.VisualStudio.Shell.Package.CreateToolWindow(Type toolWindowType, Int32 id, ProvideToolWindowAttribute tool, Object context)
   at Microsoft.VisualStudio.Shell.AsyncPackage.<CreateToolWindowAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Shell.AsyncPackage.<>c__DisplayClass45_0.<<FindToolWindowAsync>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Shell.ToolWindowCollection.ToolWindowListener.<>c__DisplayClass1_0.<<-ctor>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Threading.AwaitExtensions.ExecuteContinuationSynchronouslyAwaiter`1.GetResult()
   at Microsoft.VisualStudio.Threading.AsyncLazy`1.<>c__DisplayClass13_0.<<GetValueAsync>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Shell.AsyncPackage.<FindToolWindowAsync>d__45.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Shell.AsyncPackage.<ShowToolWindowAsync>d__46.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Community.VisualStudio.Toolkit.BaseToolWindow`1.<ShowAsync>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at MyPackage.MyToolWindowCommand.<ExecuteAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Community.VisualStudio.Toolkit.BaseCommand`1.<>c__DisplayClass10_0.<<Execute>b__0>d.MoveNext()

[reduckted]

Hmm, that's strange. Are any of your extensions overriding the InitializeToolWindowAsync method? That's the only way I can see that the context would be an Object instead of an InstantiateToolWindowData. https://github.com/VsixCommunity/Community.VisualStudio.Toolkit/blob/9c32305c83827d0bfd7c85777f9e79fc71e22c2b/src/toolkit/Community.VisualStudio.Toolkit.Shared/ToolkitPackage.cs#L55

[meadisu27]

Ok, I think I found the culprit. Solution structure is as follows:

MyPackage.VSIX.2019 - Loaded, refernces 2019 toolkit (v16) MyPackage.VSIX.2022 - Loaded and Set as Startup Project, references 2022 toolkit (v17) MyPackage.VSIX.Shared - Loaded and toolwindow code resides in this project

When I unload MyPackage.VSIX.2019 the error no longer occurs or hasn't occurred in a while.