Conflicting entry: Rate is ignored

What causes this issue?

The system ignores the rate field because the exchange rate results
form the ratio of the planning currency amount to the local currency
amount, but the entry is in local currency, so that the rate field is
meaningless.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.