You can specify an exchange rate type only for a maximum amount license

What causes this issue?

You tried to enter an exchange rate type for currency conversion
although no maximum amount is assigned to this license type. This means
that the system does not have to carry out a value update or a foreign
currency translation.

System Response

The system does not allow this entry.

How to fix this error?

Maintain the license type so that a maximum amount can be assigned to
this license type.

Error message extract from SAP system. Copyright SAP SE.