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

VN381 - Overview

• 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.

VN381 - Details

• Certainly! Here's a detailed explanation for the SAP error message VN381: Incompatible change of partner function from '&' to '&':
  
  SAP Error Message: VN381
  Text: Incompatible change of partner function from '&' to '&'!
  
  Cause
  This error occurs when you try to change the partner function in a purchasing document (such as a Purchase Order or Contract) from one partner function to another incompatible partner function. SAP enforces certain rules about partner functions in purchasing documents to maintain data consistency and business logic integrity.
  For example, if a partner function is initially set as "Ordering Address" (WE), and you try to change it to "Invoicing Party" (RI) or any other partner function that is not allowed to replace the original one, the system throws this error.
  The key reasons include:
  
  The partner function you are trying to change to is not compatible with the original partner function.
  The partner function is fixed or controlled by the document type