Prepayment error - AFTER AR CREATE_PREPAYMENT RETURN STATUS IS: U

Been trying to setup Prepayment in on OM thread, Cannot create a Prepayment in OM Payments form.

OM Calls the AR api below to create the prepayment receipt but it is returning with un-expected errors as captured in the debug as follows. Any assistance would be appreciated.

OEXVPPYB: AFTER AR CREATE_PREPAYMENT CASH_RECEIPT_ID IS:

OEXVPPYB: AFTER AR CREATE_PREPAYMENT PAYMENT_SET_ID IS:

OEXVPPYB: AFTER AR CREATE_PREPAYMENT CHECK NUMBER IS:

OEXVPPYB: AFTER AR CREATE_PREPAYMENT x_payment_response_error_code  IS:

OEXVPPYB: AFTER AR CREATE_PREPAYMENT approval_code IS:

OEXVPPYB: AFTER AR CREATE_PREPAYMENT x_msg_count IS: 4