In transactionXK02 when you try to change partner function in other langauge as EN (f.e. in ES) error message ME351 is issued:
If you logon with language: ES and change the partner function error message: ME351 appears.
The partner function 'AP' is not existing in partner schema and due to this the message is raised.
I analyed why the partner function 'AP' is determined and not 'LF'. In the customing the partner function 'AP' convered to 'PR' AND also the partner function 'LF' to 'PR'.
Transaction: VOPAN
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The problem is that the system checks the partner determination with the first entry ('AP' to 'PR'), but the partner function 'AP' is not maintained in the partner schema.
There is an inconsistencies which should be corrected.