At least one object type was not found

What causes this issue?

The corresponding object type ID's for a set of object types were read
from the database. During this at least one object type was not found.
Possible cause: The contents of the database have changed since the
last reorganization/update of the list. At least one of the object
types represented earlier has been deleted.

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.