Exchange rate of & fixed for translation from & to &

What causes this issue?

An exchange rate type is used for exchange rate &V1& / &V2& which is
defined as a fixed rate. However, the exchange rate with which the
system should continue to calculate differs from this fixed rate.

System Response

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

How to fix this error?

If necessary, ensure that your entries will not cause a deviation from
the fixed exchange rate.

Error message extract from SAP system. Copyright SAP SE.