Why the Sync Error occurs
This error occurs when a payment cannot sync to Xero because the payment amount is greater than the open balance of the bill or invoice in Xero. The amount of a payment must be less than or equal to the open balance on the bill or invoice in order to sync successfully to Xero.
How to Fix the Sync Error
Remove any duplicate manually applied payment from the bill or invoice in Xero and sync.
If the error does not clear or the payment does not need to sync, contact Customer Support for additional assistance.