“Unable to sync product eKanban order: null value in column "built_quantity_method" violates not-null”
Other potential error clues:
SetError(): # XXX
recvdoc() or recvdoc parms:
To troubleshoot this error message, check to see if this has occurred because you are trying to create an order via this API call when that order has already been created and completed and contains that exact external id/name combination.