Unhandled exception has occured when CTRL+V

I managed to trigger an Unhandled Exception error when not paying attention to my endless CTRL + Whatever-ing.

To reproduce:
1. Start SharpDevelop, I'm using version 5.1.0 (build 5216) on Win10
2. New Solution -> Windows Applications -> Windows Application, name it whatever -> Create
3. CTRL+A in your class
4. CTRL+V in some other code to replace everything
5. CTRL+S
6. CTRL+A (again)
7. CTRL+V (again)
8. Press CTRL+Z twice
"Unhandled exception has occured"

Code I was pasting: http://pasted.co/45768e0a

Exception: http://pasted.co/fd36c588