SignalR connection cannot negotiate version - signalr

Question

Iam using a hosted blazor wasm for a project that i stopped working on a few months ago. But recently i decided to change something in it, and it doesnt work anymore.
When i try to establish SignalR connection, it makes post request to https://localhost:44322/gameHub/negotiate?negotiateVersion=1 address, which always return 404 code.
Iam using iis express to host the app.
This is my first web and blazor project, so i have no idea, which information i should provide. I saw different topics about this issue, but i didnt even understand, what people submitted there.
Request info from browser debug menu
Request URL: https://localhost:44322/gameHub/negotiate?negotiateVersion=1
Request Method: POST
Status Code: 404
Remote Address: [::1]:44322
Referrer Policy: strict-origin-when-cross-origin
:authority: localhost:44322
:method: POST
:path: /gameHub/negotiate?negotiateVersion=1
:scheme: https
accept: */*
accept-encoding: gzip, deflate, br
accept-language: en-US,en;q=0.9
content-length: 0
origin: https://localhost:44322
referer: https://localhost:44322/10
sec-ch-ua: " Not;A Brand";v="99", "Microsoft Edge";v="91", "Chromium";v="91"
sec-ch-ua-mobile: ?0
sec-fetch-dest: empty
sec-fetch-mode: cors
sec-fetch-site: same-origin
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36 Edg/91.0.864.41
x-requested-with: XMLHttpRequest
Server startup.cs code
public void ConfigureServices(IServiceCollection services)
{
services.AddSignalR();
services.AddControllersWithViews();
services.AddRazorPages();
services.AddResponseCompression(opts =>
{
opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
new[] { "application/octet-stream" });
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseResponseCompression();
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseWebAssemblyDebugging();
}
else
{
app.UseExceptionHandler("/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseBlazorFrameworkFiles();
app.UseStaticFiles();
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapRazorPages();
endpoints.MapControllers();
endpoints.MapHub<GameHub>("/gameHub");
endpoints.MapFallbackToFile("index.html");
});
}
Client connection code
HubConnection hubConnection = new HubConnectionBuilder()
.WithUrl(navigationManager.ToAbsoluteUri("/gameHub"))
.Build();
await hubConnection.StartAsync();
Iam not sure if the client was making these requests when it was working fine.
I updated all nuget packages, tried to use all solutions i could find, but it didnt help.

Answer 1

You need to run your app from the server project. By default visual studio set the client project as startup project, and that was the problem.