Before you go troubleshooting all the steps linked to (although given the date, it may be too late) You may want to try logging into your Adobe CC account in a browser, View your Archived files, and delete the troublesome files from your archives.
I've run into the same problem you're having. I did what I described above and it seemed to do the trick. The effects aren't immediate. It's going to take a day or so for Adobe to catch up but the warning should go away.
Although this worked for me, just today, a new file has given me the same problem. After my fix, we'll see if the warning dialog goes away tomorrow.