A rate determination already exists for rate type &1 and rate category &2

What causes this issue?

You attempted to define a rate determination for rate type &v1& and
rate category &v2&, however, a rate determination already exists for
rate type &v1& and rate category &v2&.

System Response

Processing is canceled.

How to fix this error?

Select the <LS>Change</> function for rate type &v1& and rate category
&v2&.

Error message extract from SAP system. Copyright SAP SE.