Microsoft.JSInterop.JSException: JS object instance with ID 7 does not exist (has it been disposed?).

[fingers10]

trafficstars

Hi @jsakamoto,

When I was testing ilovedotnet using MAUI Blazor Hybrid, I noticed that the below error occurs when I navigate to blogs/step-by-step-setup-guide-for-dotnet-maui-with-visual-studio-code. The corresponding razor page MAUISetup.razor sits inside MAUIDemoComponents.razor project. I don't have any usage of the hotkeys inside this page but I get the below exception.

Microsoft.JSInterop.JSException: JS object instance with ID 7 does not exist (has it been disposed?).
E@app://0.0.0.1/_framework/blazor.webview.js:1:5123
@app://0.0.0.1/_framework/blazor.webview.js:1:2886
Promise@[native code]
beginInvokeJSFromDotNet@app://0.0.0.1/_framework/blazor.webview.js:1:2859
@app://0.0.0.1/_framework/blazor.webview.js:1:47081
@user-script:1:4:75
forEach@[native code]
@user-script:1:4:45
global code@app://0.0.0.1/blogs/step-by-step-setup-guide-for-dotnet-maui-with-visual-studio-code:1:26
   at Microsoft.JSInterop.JSRuntime.<InvokeAsync>d__16`1[[Microsoft.JSInterop.Infrastructure.IJSVoidResult, Microsoft.JSInterop, Version=9.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].MoveNext()
   at Microsoft.JSInterop.JSObjectReferenceExtensions.InvokeVoidAsync(IJSObjectReference jsObjectReference, String identifier, Object[] args)
   at Toolbelt.Blazor.HotKeys2.HotKeysContext.<>c__DisplayClass65_0.<<UnregisterAsync>b__0>d.MoveNext()
--- End of stack trace from previous location ---
   at Toolbelt.Blazor.HotKeys2.Extensions.JS.InvokeSafeAsync(Func`1 action, ILogger logger)
Toolbelt.Blazor.HotKeys2.HotKeys: Error: JS object instance with ID 7 does not exist (has it been disposed?).
E@app://0.0.0.1/_framework/blazor.webview.js:1:5123
@app://0.0.0.1/_framework/blazor.webview.js:1:2886
Promise@[native code]
beginInvokeJSFromDotNet@app://0.0.0.1/_framework/blazor.webview.js:1:2859
@app://0.0.0.1/_framework/blazor.webview.js:1:47081
@user-script:1:4:75
forEach@[native code]
@user-script:1:4:45
global code@app://0.0.0.1/blogs/step-by-step-setup-guide-for-dotnet-maui-with-visual-studio-code:1:26

Microsoft.JSInterop.JSException: JS object instance with ID 7 does not exist (has it been disposed?).
E@app://0.0.0.1/_framework/blazor.webview.js:1:5123
@app://0.0.0.1/_framework/blazor.webview.js:1:2886
Promise@[native code]
beginInvokeJSFromDotNet@app://0.0.0.1/_framework/blazor.webview.js:1:2859
@app://0.0.0.1/_framework/blazor.webview.js:1:47081
@user-script:1:4:75
forEach@[native code]
@user-script:1:4:45
global code@app://0.0.0.1/blogs/step-by-step-setup-guide-for-dotnet-maui-with-visual-studio-code:1:26
   at Microsoft.JSInterop.JSRuntime.<InvokeAsync>d__16`1[[Microsoft.JSInterop.Infrastructure.IJSVoidResult, Microsoft.JSInterop, Version=9.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]].MoveNext()
   at Microsoft.JSInterop.JSObjectReferenceExtensions.InvokeVoidAsync(IJSObjectReference jsObjectReference, String identifier, Object[] args)
   at Toolbelt.Blazor.HotKeys2.HotKeysContext.<>c__DisplayClass73_0.<<DisposeAsync>b__1>d.MoveNext()
--- End of stack trace from previous location ---
   at Toolbelt.Blazor.HotKeys2.Extensions.JS.InvokeSafeAsync(Func`1 action, ILogger logger)

This can be reproduced from latest clone of ilovedotnet repo. Please can you assist me on what is the issue here?

Thanks, @fingers10

[jsakamoto]

Hi @fingers10, Unfortunately, I could not build the "MAUI" project with the build error below.

24>------ Rebuild All started: Project: MAUI, Configuration: Debug Any CPU ------
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018: The "DefineStaticWebAssetEndpoints" task failed unexpectedly.
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018: System.ArgumentException: An item with the same key has already been added.
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.Execute()
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
24>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk.StaticWebAssets\targets\Microsoft.NET.Sdk.StaticWebAssets.targets(675,5): error MSB4018:    at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()
24>Done building project "CommonComponents.csproj" -- FAILED.
========== Rebuild All: 23 succeeded, 1 failed, 0 skipped ==========

I have no idea why such a build error happened. I used the commit 96b9ced87d37a4f0e66c646795971b2d4b5dc7c2 on your "ilovedotnet" repository for that build.

When I created a new .NET 9 MAUI Blazor Hybrid App project and ran the Windows platform on my latest version of Visual Studio 2022, it worked correctly. So that I think my development environment must not bad.

Anyway, I could not reproduce your problem on my side since the above error. If you can provide me a small sample MAUI Blazor Hybrid app that reproduces the problem, I can investigate it.

[fingers10]

Ah I understand the problem. @jsakamoto Can you do the following and do a build?

1. From the project root, switch to cd CommonComponents.
2. Now run npm install
3. Now try building the project.

The build is failing because of this following code in CommonComponents.csproj or you can simply comment the below lines inside the CommonComponents.csproj.

<Target Name="CopyChartCSS" BeforeTargets="PreBuildEvent">
  	<!-- https://jeremybytes.blogspot.com/2020/05/cross-platform-build-events-in-net-core.html -->
  
  	<ItemGroup>
  		<DataFiles Include="$(ProjectDir)\node_modules\charts.css\dist\charts.min.css" />
  	</ItemGroup>
  
  	<Copy SourceFiles="@(DataFiles)" DestinationFolder="$(ProjectDir)\wwwroot\css\" SkipUnchangedFiles="true" />
  </Target>

Thanks for pointing out. I'll add a fix. I think this should help you to build and debug the HotKey issue.

[jsakamoto]

@fingers10

Can you do the following and do a build?

I did it, including commenting out the "CopyChartCSS" target in the CommonComponents.csproj, but the build is still failing.😭

The .NET SDK version is 9.0.200 in my environment

$ dotnet --version
9.0.200

[fingers10]

@jsakamoto I was preparing a clean branch for you to proceed. But surprisingly I'm not able to reproduce the issue. I'm not sure what happened. I faced this issue several times yesterday. May be running dotnet clean might have fixed it. I'll keep an eye for a week to see if this issue occurs again. Else I'll come back and close this issue.

[jsakamoto]

@fingers10 OK, no problem. If you find any issues with this library, please let me know.😊

[jsakamoto]

Hi @fingers10, I'm going to close this issue to keep the issue list clean. But of course, as you know, please feel free to reopen this issue or create a new one as needed.

Anyway, thank you for your contributions!