System.MissingMethodException: Method not found Windows Store App Deployed on Surface RT

Question

I am developing a simple Tongue Twister Windows Store App using C#. The App works fine on my development environment (Windows 8.1 Pro, x64, Visual Studio 2013) and it only crashes when run on a Surface RT (Windows RT 8.1 Preview). When I sideload the package to the Surface, I deploy it for ARM; whereas, locally I run with x86.

The App uses the (Surface) microphone to gather the user's voice and when the button 'Start Listening' is pressed it crashes producing the following error:

System.MissingMethodException: Method not found "System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Dispose()"

I have debugged this issue remotely connecting my developer machine to the Surface but I can't make it crash. Yet the piece code that is executed when the 'Start Listening' button is pressed is:

SpeechRecognitionResult speechResult = await mRecognizer.RecognizeSpeechToTextAsync();

/** Prior code **/


private ICommand mListen;
...
mListen = new DelegateCommand<object>(OnListen);

public ICommand Listen
{
 get
        {
         return mListen;
        }
}

Thanks!