Project system ran into an unexpected problem, please report it to the product team

[blueheron786]

Describe the Issue

Error notification about an unexpected problem.

8/1/2025 1:15:34 PM
LimitedFunctionality
System.AggregateException: Project system data flow 'Workspace update handler 36344505' closed because of an exception: Cannot access a disposed object.
Object name: 'StreamJsonRpc.JsonRpc'.. (Cannot access a disposed object.
Object name: 'StreamJsonRpc.JsonRpc'.)
---> (Inner Exception #0) StreamJsonRpc.RemoteInvocationException: Cannot access a disposed object.
Object name: 'StreamJsonRpc.JsonRpc'.
   at StreamJsonRpc.JsonRpc.InvokeCoreAsync[TResult](RequestId id, String targetName, IReadOnlyList`1 arguments, IReadOnlyList`1 positionalArgumentDeclaredTypes, IReadOnlyDictionary`2 namedArgumentDeclaredTypes, CancellationToken cancellationToken, Boolean isParameterObject)
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Handlers.DynamicItemHandler.<>c__DisplayClass6_0.<<HandleProjectChangeAsync>g__ProcessAdditionsAsync|4>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Handlers.DynamicItemHandler.HandleProjectChangeAsync(IWorkspaceProject context, IComparable version, IProjectChangeDescription projectChange, ContextState state, ITelemetryOperation telemetryOperation, IManagedProjectDiagnosticOutputService logger)
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Handlers.DynamicItemHandler.HandleAsync(IWorkspaceProject context, IComparable version, IImmutableDictionary`2 projectChanges, ContextState state, ITelemetryOperation telemetryOperation, IManagedProjectDiagnosticOutputService logger)
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass43_1.<<OnEvaluationUpdateAsync>g__ProcessSourceItemsHandlersAsync|6>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass43_0.<<OnEvaluationUpdateAsync>g__ApplyProjectEvaluationAsync|2>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass46_1`1.<<OnProjectChangedAsync>g__ApplyInBatchAsync|1>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.Threading.ReentrantSemaphore.StackSemaphore.<>c__DisplayClass3_0.<<ExecuteAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.Threading.ReentrantSemaphore.StackSemaphore.ExecuteAsync(Func`1 operation, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.ProjectSystem.OnceInitializedOnceDisposedUnderLockAsync.ExecuteUnderLockCoreAsync(Func`2 action, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.OnEvaluationUpdateAsync(IProjectVersionedValue`1 evaluationUpdate)
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass42_0.<<OnWorkspaceUpdateAsync>g__ApplyUpdateWithinLockAsync|1>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass42_0.<<OnWorkspaceUpdateAsync>g__ApplyUpdateWithinLockAsync|1>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.ProjectSystem.VSCode.LanguageServices.Workspace.<>c__DisplayClass42_0.<<OnWorkspaceUpdateAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.Threading.ReentrantSemaphore.StackSemaphore.<>c__DisplayClass3_0.<<ExecuteAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.Threading.ReentrantSemaphore.StackSemaphore.ExecuteAsync(Func`1 operation, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.ProjectSystem.OnceInitializedOnceDisposedUnderLockAsync.ExecuteUnderLockCoreAsync(Func`2 action, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.ProjectSystem.DataReceivingBlockSlim`1.ProcessInputQueueAsync(InputDataBuffer inputQueue)
<--- (Inner Exception #0) 

Steps To Reproduce

Open a previously working project and hit F5 to run it

Expected Behavior

No error notification? 😅

Environment Information

OS: Windows 11 24H2

VSCode:
Version: 1.102.3 (user setup)
Commit: 488a1f239235055e34e673291fb8d8c810886f81
Date: 2025-07-29T03:00:23.339Z
Electron: 35.6.0
ElectronBuildId: 11847422
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Windows_NT x64 10.0.26100

Extension version: 1.20.35

[claudiaregio]

@drewnoakes are you able to take a look?

@blueheron786 could you please update to the latest version of C#DK and C# extensions and confirm if you are still seeing this issue? Also, are you able to share the code per chance so we can try to reproduce? If not it would be helpful if you could run the VS Code command "Developer: Open Extensions Log Folder", zip the contents, and paste them into this issue to help us debug.

[blueheron786]

Sure, here's my exthost.zip. Unfortunately, I have several projects on the go at once, so I don't remember which one this was, and I don't have concrete repro steps :(

I'll try the latest VSCode + C#DK and C# extensions, and I'll keep an eye out for this error.

[claudiaregio]

@blueheron786 That's ok, thanks for the logs! I'll see if @drewnoakes is able to see anything from those in the meantime..

[drewnoakes]

Thanks @blueheron786 for the logs. Looking through them, and at the code in question, nothing jumps out at me as obviously wrong. It seems like a service proxy is being used after having been disposed, which might be a race condition. Though given you said you were trying to F5 debug, I wouldn't expect anything to be disposed in that scenario. Maybe another error happened prior to this. Will require some more investigation.

[blueheron786]

@drewnoakes I wouldn't worry about it. If it reproduces again/regularly, I think that will make it more worthy of investigation. Considering how heavily I'm using VSCode and C#, a rare error like this is not really something to spend resources on tbh.

[claudiaregio]

Thanks @blueheron786 , going to close for now

[drewnoakes]

Thanks @blueheron786. If you see this again, please let me know. And if you can remember any exact steps you took before, it'd be good to know.