Blazor WASM doesn't hit breakpoint

Question

I have a Blazor WASM Project with version 5 assemblies and tried to activate debugging according to this article: https://docs.microsoft.com/en-us/aspnet/core/blazor/debug?view=aspnetcore-3.1

For that I made sure I updated all the assembly references and adjusted the launchsettings. The latter looks like that now:

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:62310",
      "sslPort": 44325
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "ApplySupportTool.Client": {
      "commandName": "Project",
      "launchBrowser": true,
      "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}",
      "applicationUrl": "https://localhost:5001;http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

Also these are my references in the WASM Project:

<PackageReference Include="System.Net.Http.Json" Version="3.2.0-preview5.20210.3" />
<PackageReference Include="Microsoft.AspNetCore.Components.DataAnnotations.Validation" Version="3.2.0-preview2.20160.5" />
<PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="3.2.0-preview5.20216.8" />
<PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Build" Version="3.2.0-preview5.20216.8" PrivateAssets="all" />
<PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="3.2.0-preview5.20216.8" PrivateAssets="all" />
<PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Runtime" Version="3.2.0-preview5.20216.1" />
<PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Authentication" Version="3.2.0-preview5.20216.8" />

For testing I copied over the "Counter" page from the default project. But when I hit F5 to debug the breaking point in the IncrementCount method doesn't turn red. I tested in a new created default project and there it works, so I pressume Visual Studio Preview, Edge and .net core has the correct version.

What I noticed is this warning in the dev console which only appears in my existing project, but not in the new created default project:

DevTools failed to load SourceMap: Could not load content for chrome-extension://ndcileolkflehcjpmjnfbnaibdcgglog/include.preload.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME

Is there something other I have to add or adjust for this to work? In the article above I couldn't find anything as far as I can see.

https://stackoverflow.com/questions/56267303/blazor-client-side-debugging have you seen this post? possible duplicate — Diogo Neves, Jun 25 '20 at 19:17

sw1337 · Answer 1 · 2020-08-20T06:00:13.147

This is a known issue in Blazor projects at this time. The debugger launches slower/quicker than the project assembly and doesn't have time to "see" the assembly. Here is my fix until they solve this. I add a delay in Program.cs so that when the project launches in debug mode, it gives the debugger time to attach properly. I used 5000 ms but you may have to increase this value if your machine is slower than mine.

    public class Program
    {
        private static async Task DebugDelayAsync()
        {
#if DEBUG
            await Task.Delay(5000);
#endif
        }

        public static async Task Main(string[] args)
        {
            await DebugDelayAsync();

            (...)
        }
    }

i tried many solutions even one from official aspnetcore repo but this worked like a charm ... lol — Alok, Oct 21 '20 at 14:02

score 2 · Answer 2 · answered Feb 11 '21 at 11:02

2

This may help someone. In my case I deleted the hidden .vs folder for the solution and break points worked again. In addition this fixed an issue where Chrome Debugging would not work any longer.

answered Feb 11 '21 at 11:02

Patrick

1,545
12
20

score 0 · Answer 3 · edited Jul 31 '20 at 14:21

0

Something similar happened to me a few days ago.

The steps I took were as follows:

Edit the debug profile. In my case, I edited the port and removed the https protocol option.
Compile and check that the debugging points were working again.
Edit the debug profile to return to the initial configuration. I didn’t undo the changes, I edited them by hand again

edited Jul 31 '20 at 14:21

Dharman

21,838
18
57
107

answered Jul 31 '20 at 14:15

Hazuky

1
1

score 0 · Answer 4 · answered Mar 25 '21 at 22:28

if earlier methods didn't work also try:

implement the DebugDelay from the top answer.
with notepad, open [your project]\Client\Properties\launchSettings.json
Under iisSettings.. "applicationUrl": "http://localhost:50454", copy the local host .eg. http://localhost:50454
In Visual Studio IDE, Debug, [my app].server.debug* properties / webserver settings / App URL. Paste in your clipboard.

don't ask me why it worked but it did, the annoying 'Unbound breakpoint will not be hit' was gone.

Blazor WASM doesn't hit breakpoint

4 Answers4

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