Blank dock, command+tab menu icon for application - RubyMine 7.0
I recover from all sort of temporary dock corruption by killing the dock after saving work and getting ready to restart the Mac.


killall Dock from terminal app
log out and back in
restart the Mac


Barring that, you've got more serious corruption, but let's start with the quick triage first.

The next steps would be to make a new user account and repeat installing your app on that user’s desktop and drag it into the dock.