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 exchange rate. However, the exchange rate with which
the system should continue to calculate is different from this fixed
exchange rate.
INCLUDE 'CUSTOMIZED_MESSAGE_INFO' OBJECT DOKU ID TX

Error message extract from SAP system. Copyright SAP SE.