Runtime error after adding Microsoft.AspNetCore.Session and Microsoft.Extensions.Caching.Memory

All I ever wanted was to use TempData in my application 

So long story short, my project.json dependencies now looks like this:

"dependencies": {"Microsoft.ApplicationInsights.AspNetCore": "1.0.0","Microsoft.AspNetCore.Authentication.Cookies": "1.0.0","Microsoft.AspNetCore.Diagnostics": "1.0.0","Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.0.0","Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0","Microsoft.AspNetCore.Mvc": "1.0.1","Microsoft.AspNetCore.Razor.Tools": {"version": "1.0.0-preview2-final","type": "build"
    },"Microsoft.AspNetCore.Routing": "1.0.1","Microsoft.AspNetCore.Server.IISIntegration": "1.0.0","Microsoft.AspNetCore.Server.Kestrel": "1.0.1","Microsoft.AspNetCore.Session": "1.0.0-rc2-final","Microsoft.AspNetCore.StaticFiles": "1.0.0","Microsoft.EntityFrameworkCore.SqlServer": "1.0.1","Microsoft.EntityFrameworkCore.SqlServer.Design": {"version": "1.0.1","type": "build"
    },"Microsoft.EntityFrameworkCore.Tools": {"version": "1.1.0","type": "build"
    },"Microsoft.Extensions.Caching.Memory": "1.1.1","Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0","Microsoft.Extensions.Configuration.Json": "1.0.0","Microsoft.Extensions.Configuration.UserSecrets": "1.0.0","Microsoft.Extensions.Logging": "1.1.1","Microsoft.Extensions.Logging.Console": "1.0.0","Microsoft.Extensions.Logging.Debug": "1.0.0","Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0","Microsoft.NETCore.App": {"version": "1.0.1","type": "platform"
    },"Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0","Microsoft.VisualStudio.Web.CodeGeneration.Tools": {"version": "1.0.0-preview2-final","type": "build"
    },"Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {"version": "1.0.0-preview2-final","type": "build"
    }
  },

Now my project compiles, but I get a runtime error, which appears to have issue with services.AddSession() in my ConfigureServices (Startup.cs). Any ideas?

error message:

Message=Could not load type 'Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions' from assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=1.1.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.