Change is the same as the amount of the cash payment

What causes this issue?

You have selected the payment amount such that the repayment amount is
exactly the amount of the cash payment. This means that the complete
cash payment should be given as change.

System Response

A complete refund of the cash payment is not possible.

How to fix this error?

Remove the cash payment.

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.