Message SAP WXP383 - Plan version &1 is required for external application &2

Diagnosis
You wish to delete plan version &V1&, however, this is required forexternal application &V2&. If you delete this plan version, theexternal application will not be able to read any plan data.

System Response
The plan version cannot be deleted.

Procedure
If you still want to delete the plan version, you must first define adifferent version in the definition of external application &V2&.