Blazor WebAssembly .Net 8 application broken due to new updates. Need your help in to review what is broken piece and guide.

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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Please do not declare this question as DUPLICATE, as we are in need of your expert advice to resolve this issue.

Program.cs

Startup.cs

LendingAuthority.Client.csproj

wwwroot.zip

LendingAuthority.Server.csproj

LendingAuthority.Shared.csproj

Solution-Packages-View.png
[severity:I’m unable to use this version]
This is a big blazor webAssembly application went live in PROD with .Net 5 using architecture of ( Client , Server and Shared Projects ).

Then with time we migrated to 6 and also to 8.0 , everything was working fine without any issue. But visual studio update 17.12.3 version breaks this application. we searched every piece of information to apply a fix but unfortunately it did not worked out. So need your help on this please to guide us a possible fix -

So far we have tried -

1. Implementing BrotliDecode. in Index.Html file.
2. LoadBootResource for DotNet.js in order to clean cache.
3. Implemented <Script src=“_framework/Blazor.webassembly.js?v=8.0.4” autostart=“False” />
4. In Startup.cs file implemented endpoint. MapGet ( “/ clear-site-data”, async context=>
   { context. Response.Headers[“Clear-Site-Data”] = ““cookies”,“storage”,“cache””;} );
5. Making the correct sequence of Middleware service
   a) first using app. UseBlazorFrameworkFiles();
   b) then using app. StaticFiles ();
6. I deployed website with a NEW DNS also, just to get rid of if it is cached DotNet.js file or any other blazor web assembly framework files.
7. Also visited 100’s of github questions and answers. based on those suggestions tried to implement the code changes.

but still facing error = Mono_WASM_Load_runtime () faied typeerror: u.isDebuggingSupported is not a function.
The version of dotnet.runtime.js is different from the version of dotnet.js !
The version of dotnet.native.js is different from the version of dotnet.js !

Please do not declare this question as DUPLICATE, as we are in need of your expert advice to resolve this issue.

These .NET SDK installed in my machine.
C:>dotnet --list-sdks
3.1.426 [C:\Program Files\dotnet\sdk]
5.0.214 [C:\Program Files\dotnet\sdk]
5.0.408 [C:\Program Files\dotnet\sdk]
6.0.428 [C:\Program Files\dotnet\sdk]
7.0.317 [C:\Program Files\dotnet\sdk]
8.0.404 [C:\Program Files\dotnet\sdk]
9.0.101 [C:\Program Files\dotnet\sdk]

These .NET RUNTIME installed in my machine.

C:>dotnet --list-runtimes
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Thanks,
BK

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Original Comments

Kumar, Baljeet on 1/14/2025, 10:59 PM:

These .NET SDK installed in my machine.
C:>dotnet --list-sdks
3.1.426 [C:\Program Files\dotnet\sdk]
5.0.214 [C:\Program Files\dotnet\sdk]
5.0.408 [C:\Program Files\dotnet\sdk]
6.0.428 [C:\Program Files\dotnet\sdk]
7.0.317 [C:\Program Files\dotnet\sdk]
8.0.404 [C:\Program Files\dotnet\sdk]
9.0.101 [C:\Program Files\dotnet\sdk]

These .NET RUNTIME installed in my machine.

C:>dotnet --list-runtimes
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

C:>

Program.cs

Startup.cs
wwwroot.zip
LendingAuthority.Client.csproj
LendingAuthority.Server.csproj
LendingAuthority.Shared.csproj
Solution-Packages-View.png

Feedback Bot on 1/15/2025, 08:50 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

Kumar, Baljeet on 1/17/2025, 05:34 PM:

Could you please share an update on this ? Out project team is kind of stuck and it has become very urgent to make it working.

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• [Blazor WASM] Upgrading project to .NET 8.0.10 breaks WASM #58313

[javiercn]

We believe this is a dupe of #58313

#63161 tracks backporting a fix to 8.0

For .NET 9.0 and 10.0

We implemented fingerprinting for hosted Blazor WebAssembly scenarios in .NET 9.0 and extended it to standalone scenarios in .NET 10.0. The implementation appends content-based hashes to static asset paths and generates importmaps in the HTML to ensure proper cache-busting when files change.

For .NET 8.0

For .NET 8.0 users experiencing the dotnet.js caching issue, we believe you can add an importmap to your HTML as a workaround:

<script type="importmap">
{
  "imports": {
    "./dotnet.js": "./dotnet.js?v=8.0.x"
  }
}
</script>

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