&1: Error when adding bank details for partner &2

What causes this issue?

You want to add bank details to an existing partner, using the payment
plan interface.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

An error occurred.

How to fix this error?

Add the bank detials online, and evaluate the error message that may
occur.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.