System.TypeLoadException using "services.AddMvc();"

Hello,

I'm a beginning programmer with ASP.NET and am having trouble resolving an exception using the "services.AddMvc()" method in my project. I've dug around in the threads a bit and my Google-fu hasn't been able to find any solutions. If you need any more information let me know.

Raw Exception Details:

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeLoadException: Could not load type 'Microsoft.Extensions.DependencyInjection.Extensions.ServiceCollectionExtensions' from assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.
   at Microsoft.Extensions.DependencyInjection.MvcCoreServiceCollectionExtensions.AddMvcCore(IServiceCollection services)
   at Microsoft.Extensions.DependencyInjection.MvcServiceCollectionExtensions.AddMvc(IServiceCollection services)
   at TheWorld.Startup.ConfigureServices(IServiceCollection services) in C:\Pluralsight Tutorials\ASP.NET App with MVC etc\TheWorld\src\TheWorld\Startup.cs:line 19
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.AspNetCore.Hosting.Internal.ConfigureServicesBuilder.Invoke(Object instance, IServiceCollection exportServices)
   at Microsoft.AspNetCore.Hosting.Internal.WebHost.EnsureApplicationServices()
   at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()

Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace TheWorld
{
    public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            app.UseStaticFiles();

            app.UseMvc();
        }
    }
}

project.json

{"dependencies": {"Microsoft.AspNetCore.Diagnostics": "1.0.0","Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final","Microsoft.AspNetCore.Server.IISIntegration": "1.0.0","Microsoft.AspNetCore.Server.Kestrel": "1.0.0","Microsoft.AspNetCore.StaticFiles": "1.0.0","Microsoft.Extensions.Logging.Console": "1.0.0","Microsoft.NETCore.App": {"version": "1.0.0","type": "platform"
    }
  },"tools": {"Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
  },"frameworks": {"netcoreapp1.0": {"imports": ["dotnet5.6","portable-net45+win8"
      ]
    }
  },"buildOptions": {"emitEntryPoint": true,"preserveCompilationContext": true
  },"runtimeOptions": {"configProperties": {"System.GC.Server": true
    }
  },"publishOptions": {"include": ["wwwroot","web.config"
    ]
  },"scripts": {"postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}