Does the program open OK? If so, try resetting the preferences file. Go to Edit>Preferences>General tab and click the Reset Preferences on next launch button.
If you can't open the program, reset the preferences by pressing Alt+Shift+Ctrl (Windows) immediately after launching the program. A message should pop up asking if you want to delete the Settings file. Answer OK. I think you press Opt+Shift+Cmd on a Mac.