Null reference pointer was passed to the stub when not debugging with IE

Question

In VS2012, my web project debugs fine like always. I use IIS Express. Today, I installed VS 2013 and when I press F5 to debug, I get

Answer 1

Undesirable workaround for a seemingly related problem (not an answer):

I created a new Silverlight project in VS2013 (express edition, C#) and got nearly the same error upon trying to run the application in debug mode (by pressing F5). The error message also ended with 'A null reference pointer was passed to the stub.'

I set my default browser to IE10 and now the debug mode for Silverlight applications in C# in VS 2013 (express edition) works fine.