The following are potential reasons why Quicken Cloud Sync Errors may occur.
When a user tries to log into Quicken's mobile and desktop versions with different usernames, a synchronizing error is shown. Consequently, take care to use the same login credentials for both versions (desktop and mobile).
It's possible that the Quicken server itself is to blame for the issue. In this circumstance, the error might be self-corrected.
A poor internet connection can also result in problems with Quicken's cloud sync.