[Zubersoft]

Well you can always create a backup under Settings->Backup and Restore->Backup Library and then upload that to the cloud or keep it somewhere safe. That is actually a more extensive backup than using the sync to cloud folder option, as it also contains all of your application settings. Having said that, I would like to help you get the sync working. It looks to me like one of the songs/files may be a problem. If you go to Settings->Other Settings->Find Missing Files, are any files reported as missing? I'm assuming the sync is failing in the same spot every time, correct? Do you know which song is related to the file listed in your screenshot? Is anything different about that song? Can you delete that song, recreate it and then try the sync again? 

Alternatively, if you want to share a library backup file with me through Google Drive (share it with mike@zubersoft.com), I'd be happy to try synchronizing to the cloud to see if I encounter the same issue and can pinpoint any problems.

Mike