If you see the error:
InvoiceAddRs statusCode=3120 statusSeverity=Error statusMessage=Object "12345678-123456789" specified in the request cannot be found. QuickBooks error message: Invalid argument. The specified record does not exist in the list,
Please contact ServiceTrade support at firstname.lastname@example.org. ServiceTrade will need to clear and re-sync customer list on integration-production.
Updated January 22, 2019