I'm posting this to offer a fix for those who may encounter the above error. I have nearly 20 years experience with Access, and I never encountered the error until today. It just seemed to materialize out of nowhere but it occurred with every event procedure on one form. After troubleshooting my own work and finding nothing amiss I started searching online forums for help. There were many suggestions, including uninstalling and reinstalling Access (which I did to no avail), and after trying all that I could, I finally, out of sheer frustration and lack of other direction, decided to try the routine I use to correct Return Without GoSub error. It involves pasting the following, including quotation marks, into the run window.
"C:\Program Files\Full path to Access\MSACCESS.EXE" /decompile "Full path to your db.ACCDB"
It worked fabulously. The problem was corrected within 30 seconds.
Because I beat my brains out trying to solve this and because I came upon a simple and effective fix I wanted to share it with others. Even if you've never seen the error before, I suggest you hang on to the fix. It took me two decades, but I finally bumped into it, and if you do a Google search like I did you'll see it's not so uncommon. It'll likely happen to you someday as well.