How To Fix VN381 - Incompatible change of partner function from '&' to '&'!

SAP Error Message - Details

• Message type: E = Error

• Message class: VN - Nachrichtensteuerung

• Message number: 381

• Message text: Incompatible change of partner function from '&' to '&'!

What causes this issue?

The partner function was changed for an existing MESSAGE object with at
least one assigned recipient. The changed partner function does not
correspond to the first assigned recipient of the recipient list.

System Response

The system does not accept the change made to the partner function.

How to fix this error?

If an object exists with at least one assigned partner, the partner
function can only be changed to a value that is linked to the same
partner function as the source partner function. You have three
options:
Reset the partner function.
Assign a partner for the changed partner function by choosing possible
entries.
Branch to "Communication" and assign a partner with a different partner
type. The relevant partner function will be returned.

Error message extract from SAP system. Copyright SAP SE.