Thank you for responding. Although that link's title is not the problem I was facing, I tried the steps in any case. Deleting the OPM.db file did not have any effect. However, uninstalling creative cloud then downloading and reinstalling it worked, and the problem is fixed. For the reference of anyone who runs into the same problem and winds up on this thread, I did not use the CS cleaner mentioned in the linked help article.
Marking question as answered.