Selected bank details for vendor &1 are not valid

What causes this issue?

The bank details were copied from the template document. Checking of
bank details from the template was activated. You want to use bank
details for a vendor for payment, but these bank details are not in the
vendor master record or are no longer valid.

System Response

The request cannot be saved.

How to fix this error?

If the bank details do not currently exist in the master record but are
to be retained, you can confirm this by accessing the payer data (Ctrl +
F10) or by deriving valid bank details by entering the payee again.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.