Copy Paste Not Working

The copy-paste function is not working for me, both before and after updating to the latest version. The keyboard controls and using the Edit -> copy/paste functions are not working. Interesting, the cut feature works. I have tried to copy/paste within notes, measures, and entire staffs and nothing is working. I even went back to an old score that I used a lot of copy/paste on and it doesn't seem to work either. Any help is appreciated!