Aspnetcore.docs: Cannot negotiate SingalR with WASM client.

[afuzzyllama]

When following the "Use ASP.NET Core SignalR with Blazor WebAssembly" tutorial, I cannot get a successful negotiation between a WASM client and localhost. The returned status is always 404

Running with:

• Client
  
  
  
  • Microsoft.AspNetCore.Components.WebAssembly 3.2.0-preview4.20210.8
  
  
  • Microsoft.AspNetCore.SignalR.Client 3.1.3
  
  
• Server
  
  
  
  • Microsoft.AspNetCore.Components.WebAssembly.Server 3.2.0-preview4.20210.8
  
  

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Document Details

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• ID: 08de9daf-79aa-ee76-431e-f2432f8d691e
• Version Independent ID: 1a1ee728-1741-c82a-75e1-06159709935b
• Content: Use ASP.NET Core SignalR with Blazor WebAssembly
• Content Source: aspnetcore/tutorials/signalr-blazor-webassembly.md
• Product: aspnet-core
• Technology: aspnetcore-tutorials
• GitHub Login: @guardrex
• Microsoft Alias: riande

[guardrex]

Hello @afuzzyllama ... I'll see if I can repro your experience here on Monday.

[afuzzyllama]

I've tried to figure out more on my end, but trying to configure logging for SignalR produced nothing. I could not get the Core Web Server to output anything to the console in Visual Studio following Logging and diagnostics in ASP.NET Core SignalR. In the browser, setting logging to debug for the wasm app did not produce anything related to SingalR either (setting builder.Logging.SetMinimumLevel(LogLevel.Trace); in Program.Main. The 404 is the only in formation I get regarding the failure.

[guardrex]

I'll take a look, but I'm slammed at the moment 🏃😅. I'll try to get to this by the end of the day. 🤞

You could try reaching out to the usual support channels in the meantime ... see if anyone else has tried it and is having trouble.

• Stack Overflow
• ASP.NET Core Slack
• ASP.NET Gitter

[afuzzyllama]

No rush! I just wish I could provide you with more than essentially "why isn't this working!"

[guardrex]

That's ok ... things break from time-to-time and this isn't all that unusual during preview. I'll just walk the tutorial like you did from scratch. If I get the same outcome, then we'll open an issue for engineering. If I walk it and it works, I'll toss my solution up on GH for you to compare to your solution.

The thing about my testing first that's helpful on the MS end is that if it does work here, then we might be able to discover the problem without opening a new engineering issue on top of _a gazillion other engineering issues_.

I'm slammed

... and they're equally (if not more) slammed than I am. 🏃

[afuzzyllama]

So I have an update. It does work, I just wasn't launching my project correctly. In Visual Studio if you launch the razor page with the "View in Browser" command, it doesn't launch the server project. It seems to launch some other default server 🤷 The project must be launched with either Debug (F5) or Start Without Debugging (Crtl+F5).

Thanks for your responses, you can take this off your plate!

[guardrex]

:beers: _GrEaT!_

Before we close this tho, let me adjust that VS and VSC instruction and the package versions. We called out running the app without debugging. Now, VS and VSC can say/show that running with debugging is ok based on the recent preview updates since this document was first put up, when you didn't have a choice about it. Also, this is Preview 1, so it should go to Preview 4 now.

I'll adjust the doc and then this issue will close automatically when the PR merges.