It looks like the Adobe CoreSync preference files have become corrupted, so syncing is not working any more. To solve the problem, you can delete the corrupted files and re-start Adobe CC. The new Adobe CoreSync preference files will be created and syncing should work as before.
Here is what to do:
1. Completely exit all Adobe CC programs
2. Go to this location:
[Macintosh HD]/Users/[your Mac username]/Library/Application Support/Adobe/CoreSyncSync
3. Find and delete (move to Trash) any file that has *.db extension or a variation such as *.db-wal
4. Empty the Trash. In case you are unable to delete those files or empty the Trash, restart your computer and try again
5. After you have deleted those files, start Adobe CC and check the results
In case you experience the same problem on your other computer, repeat the same instructions.
Let me know if it solved the problem.