Class type &1: class &2 is not valid today

What causes this issue?

You want to allocate an object to a class or start a search for
objects. However, class &V2& with class type &V1& is not valid.
Today's date is not within the validity period of the class.

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.