The local currency amount/rate will be deleted

What causes this issue?

As neither the local currency rate nor the local currency amount have
been fixed, the local currency entries are reset and determined when
posting in Financial Accounting based on the current exchange 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?

Error message extract from SAP system. Copyright SAP SE.