I have started getting this error message from creative cloud, it is rather annoying as it interupting my workflow. I have restarted the computer and I have repaired the installation. It means all the files on this computer are not syncing with Adobe CC.
you may have a corrupt local file in your cc folder. test by closing cc, move all your linked local files and leaving your shared folder empty. restart cc and see if it will sync.
if that fails to solve the problem and all your files were restored to your sync'd folder,
1. resetting the cc app: To reset the Creative Cloud desktop app, make sure it's in the foreground, then press: