Characteristic & not valid as of &

What causes this issue?

Characteristic &v1& has a deletion indicator. The characteristic is no
longer valid on &v2&. As of this date, you cannot use the
characteristic in its current state.

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?

You can remove the deletion indicator in the characteristic as of the
date you entered (&v3&), using the change function and a valid change
number. The deletion indicator is deleted automatically, and the
characteristic is reactivated in the system as of &v3&.

Error message extract from SAP system. Copyright SAP SE.