Why the sync error occurs

This error occurs when the QuickBooks Online account attempting to connect to sync is a Sandbox account or the QuickBooks Online account was recently upgraded from sandbox to full account.

How to fix the sync error

To resolve this error, disconnect, and reconnect the sync:

1. Select Settings
2. Select Setup under Sync
3. Select Disconnect
4. Select Settings
5. Select Setup under Sync
6. Select Connect to set up the sync again