SignalR /signalr/hubs 404 Not Found

Question

I am trying to deploy a SignalR site on IIS. Code all works fine in VS. But getting the 404 not found error trying to resolve signalr/hubs so far I have tri

Answer 1

there are potentially many causes of this 404 - a few common ones can be found by

• Hit the url in the browser /signalr/hubs - if there is an error, you will see the full error come back.
• check for duplication of HubName attribute if you have base class
• ensure you have the correct version referenced in all projects (as to avoid binding errors)

Answer 2

The reason of this 404 error is hubs are not mapped, previously it would have to be done as answered by SimonF. If you are using SignalR version 2 RouteTable.Routes.MapHubs(); is now obsolete. For mapping hubs you can create a startup class as below.

[assembly: OwinStartup(typeof(WebApplication1.Startup))]
namespace WebApplication1
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // Any connection or hub wire up and configuration should go here
            app.MapSignalR();
        }
    }
}

referenace : http://www.asp.net/signalr/overview/releases/upgrading-signalr-1x-projects-to-20

Answer 3

For me the solution was to reinstall all the packages and restore all the dependecies.

Open nuget powershell and use this command.

Update-Package -Reinstall

Answer 4

In my case, I lose some owin dependencies then I got the 404 NotFound error.

When I added following dependencies, I retrieve the proxy javascript file clearly from expecting URL. Like URL:1111/singlar/hubs

• Microsoft.Owin
• Microsoft.Owin.Core
• Microsoft.Owin.Host.SystemWeb
• Microsoft.Owin.Security
• Owin

Hope the answer helps someone.

Answer 5

The order of route registration matters. I had this exact problem and fixed it by ensuring my global.asax.cs looked like this:

public class MvcApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        RouteTable.Routes.MapHubs();

        WebApiConfig.Register(GlobalConfiguration.Configuration);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
    }
}

This was in a web site using SignalR, MVC and WebApi all together.

Answer 6

Try adding a wildcard application map to your server to help map the unknown extension in the script URL "~/signalr/hubs"