SAP Message WP632 - Internal vendors are not allowed for purchase order generation

Diagnosis
Vendor &V1& is an internal vendor. You must enter an external vendor sothat you can automatically create a purchase order for material &V2& inthe background.

System Response
You can enter the correct vendor for the goods receipt item by usingthe following transaction.
The transaction is started automatically immediately after thisinformation screen and is supplied with values from the goods receiptinterface.