Error when converting &1 to &2

What causes this issue?

The system could not translate the amounts into the display currency
because exchange rates are missing.

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?

Inform the person responsible for Customizing.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.