Inv.supp. &1: End of validity period should be after the beginning

What causes this issue?

The validity period for investment support measure &V1& has to be
defined within a specific time period.
You defined an end date for the validity period that is before the
start date of the validity period.

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?

Correct your entry.

Error message extract from SAP system. Copyright SAP SE.