Why the sync error occurs
This error occurs when invoices or records are created while a sync is in progress.
How to fix the sync error
If an invoice or record didn't sync, edit the invoice number to trigger an update to the record on a subsequent sync:
- Edit the invoice number by adding an asterisk
- Run the sync
If the invoice syncs, edit the invoice or record again to remove the asterisk. Sync one more time to clean up the record.