Error: End Operating Unit is Invalid

Hello

We've recently setup a new Operating Unit and Inventory Organization; the OU reference an existing SOB and Business Group.

When creating Purchase Orders for that OU, we get an error message in the shipment screen.  It says 'Error: End Operating Unit is invalid' when you navigate into the Org field.

If we save the purchase order before navigating to the shipment screen, we do not get this error message.

Has anyone seen this behaviour before and knows how to resolve?

Best Regards

Mark T. Kehoe