Enter the following code into an open .csx file in the Visual Studio editor and then uncomment the commented line.
Window CreateWindow(Action action)
var w = new Window();
if (action != null)
var w = CreateWindow(() =>
// w.Content = new TextBlock("This code makes no sense");
Visual Studio will crash (at least on CTP3).
Editor should highlight syntax/compilation error, but Visual Studio should not crash.