Bank number &1 is specific to Switzerland/Lichtenstein

What causes this issue?

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

QR ID's within the range of 30000 - 31999 are reserved for QR IBAN.

System Response

QR IBAN could be used only for QR IBAN payments (QR IBAN + QR
Reference).

How to fix this error?

Use bank partner type with IBAN which is not QR IBAN.

Error message extract from SAP system. Copyright SAP SE.