No assembly found containing an OwinStartupAttribute

No assembly found containing an OwinStartupAttribute, someone asked me to explain?

I got the following error while running the application. I have created a simple chat application using signalR in mvc.  I have installed signalR in the project by nuget package manager console and registered signalR hub in the page.

The following errors occurred while attempting to load the app.
- No assembly found containing an OwinStartupAttribute.
- No assembly found containing a Startup or [AssemblyName].Startup class.
To disable OWIN startup discovery, add the appSetting owin:AutomaticAppStartup with a value of "false" in your web.config.
To specify the OWIN startup Assembly, Class, or Method, add the appSetting owin:AppStartup with the fully qualified startup class or configuration method name in your web.config.

No assembly found containing a Startup or [AssemblyName].Startup class


It was resolved by adding this code in the startup class [assembly: OwinStartup(typeof(MymvcApp.Models.StartUp))] above the namespace and run the application working fine. To know more detail refer singnalR example mvc.

using Microsoft.Owin;
using Owin;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
[assembly: OwinStartup(typeof(MymvcApp.Models.StartUp))]

namespace MymvcApp.Models
    public class StartUp
        public void Configuration(IAppBuilder app)

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