Key Editor Freezes Cubase

Hi, I’m new to this forum and I’m hoping you guys can help me out. I’m using Cubase 7.5 (love it) and have never had any issues, until now. Suddenly, when I try to open the key editor on a MIDI track, cubase freezes. I can’t even close cubase without opening the task manager and clicking end task (I’m running Windows 7 Pro 64). Everything else seems to work normally including adding a MIDI track and recording in a MIDI track, but as soon as I try to open the key editor by either double clicking on a MIDI track or going to “MIDI” and clicking “Open Key Editor”, cubase freezes. I’ve tried restarting the computer, and opening a different project but it still freezes every time I double click a MIDI track. Any ideas??? Thanks, Ron

In case this happens to anyone else, resetting the preferences fixed this problem.