This error message happens when an invoice is being downloaded from ServiceBox to QuickBooks Desktop and the QuickBooks customer record that is linked to the customer, job site or work order for the invoice is not found.
This can happen when the record has been deleted or inactivated in QuickBooks Desktop.
To fix this issue, you should unlink the customer, jobsite or work order in ServiceBox from the QuickBooks customer by editing the record in ServiceBox, unchecking the link check box at the bottom of the screen and saving.