Intermittent PO receipt issue

In 12.1.3. we have Ship-To locations that are used across multi operating units,
they do not have Inventory Organization assigned.

Intermittently from the purchase orders raised using these locations when
receiving is attempted an error is thrown.

Error
Your receipt could not be created successfully due to an unexpected error.
Please contact your system administrator with the following information
for further assistance.
"rvtptcontrol failed RVTTH-445: Subroutine No transaction Flow defined for these two operating units:
BIS - Operating Unit and UKTI Prog - Operating Unit.
Action: Please use Defined Intercompany Transaction Flow form to"

Purchase orders that exhibit this issue have one operating unit at PO header level