TypeLoadException in Microsoft.AspNetCore.Server.Kestrel on startup for .NET Core 1.1 project

Question

We are trying to port our .Net 4.5 project(Web-Api) to .Net Core.

It runs fine for every developer but me. Additionally we switched to VS 2017 RC recently.

The programm starts but crashes on the first request:

-InnerException {System.TypeLoadException: Method 'get_ContentLength' in type 'Microsoft.AspNetCore.Server.Kestrel.Internal.Http.FrameRequestHeaders' 
 from assembly 'Microsoft.AspNetCore.Server.Kestrel, Version=1.1.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.Reset()
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Frame.Start()
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Connection.Start()
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.ListenerPrimary.DispatchConnection(UvStreamHandle socket)
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.TcpListenerPrimary.OnConnection(UvStreamHandle listenSocket, Int32 status)
at Microsoft.AspNetCore.Server.Kestrel.Internal.Http.Listener.ConnectionCallback(UvStreamHandle stream, Int32 status, Exception error, Object state)
at Microsoft.AspNetCore.Server.Kestrel.Internal.Networking.UvStreamHandle.UvConnectionCb(IntPtr handle, Int32 status)
at Microsoft.AspNetCore.Server.Kestrel.Internal.Networking.Libuv.NativeMethods.uv_run(UvLoopHandle handle, Int32 mode)
at Microsoft.AspNetCore.Server.Kestrel.Internal.Networking.Libuv.run(UvLoopHandle handle, Int32 mode)
at Microsoft.AspNetCore.Server.Kestrel.Internal.KestrelThread.ThreadStart(Object parameter)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.AspNetCore.Server.Kestrel.Internal.KestrelThread.<StopAsync>d__45.MoveNext()}  System.Exception {System.TypeLoadException}

I tried different versions of Microsoft.AspNetCore.Server.Kestrel to no avail. Deleted and reset every cache of VS I know of and reinstalled .NET Core and VS 2017 RC

The proj-file:

  <ItemGroup>
    <PackageReference Include="adremes.Common" Version="1.3.0" />
    <PackageReference Include="adremes.Data" Version="3.0.1" />
    <PackageReference Include="AutoMapper" Version="5.2.0" />
    <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Routing" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.SignalR.Server" Version="0.2.0-preview2-22683" />
    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="1.1.0-preview1-23121" />
    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity" Version="1.1.0" />
    <PackageReference Include="DocumentFormat.OpenXml" Version="2.7.1" />
    <PackageReference Include="AspNet.Security.OpenIdConnect.Server" Version="1.0.0-beta7-final" />
    <PackageReference Include="AspNet.Security.OAuth.Validation" Version="1.0.0-alpha3-final" />
    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.1" />
    <PackageReference Include="System.Runtime.Serialization.Primitives" Version="4.3.0" />
  </ItemGroup>

Answer 1

The issue was fixed by reverting

<PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="1.1.0-preview1-23121" />

back to

<PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="1.0.0" />

The issue persisted with the stable 1.1.0 version.

Why it worked for some developers and not for others is still a mistery.