I appear to be having similar syncing issues as others have noted here. CC desktop app just seems to "sync" endlessly and occasionally I get the "unable to sync" due to server error dialogue.
I have dozens of files that don't seem to want to sync anymore (and they synced fine previously).
I have tried all the options I have read about in this forum. I even emptied my CC folder and tried to sync it empty (even permanently deleted my archive folder) but I still can't seem to get some files to sync reliably.