FileLoadException on 'Microsoft.Owin'

Question

So I have installed SignalR through Nuget and it is depending on Microsoft.Owin which it then installed. Whenever I run my application it throws a FileLoadException in the Startup.cs om the app.MapSignalR(); line. It says "File or assembly 'Microsoft.Owin, Version=2.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies could not be loaded. The manifest definition of the found assembly do not match the reference of the assembly."

I am sure it includes the Microsoft.Owin.dll but when I try to reinstall it through Nuget it says it could not reinstall the Microsoft.Owin.XML

Startup.cs

using Microsoft.Owin;
using Owin;

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

Answer 1

The latest version of SignalR relies on Microsoft.Owin 2.0.2.0, not 2.0.1.0. See the following tutorial- you'll want to add Microsoft.AspNet.SignalR.SelfHost in the package manager, not Microsoft.Owin.

http://www.asp.net/signalr/overview/signalr-20/getting-started-with-signalr-20/tutorial-signalr-20-self-host

Answer 2

Sometimes packages refer to specific versions of other packages. You can try to add a binding redirect for Microsoft.Owin in your web.config file (in the <runtime> section):

<dependentAssembly>
  <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" />
  <bindingRedirect oldVersion="0.0.0.0-2.1.0.0" newVersion="2.1.0.0" />
</dependentAssembly>

This tells everything that references an older version than 2.1.0.0 to use 2.1.0.0 instead.