Diagnosis
You want to implement an event for the object type. However, this eventis inherited from a supertype and therefore cannot be implemented.

Procedure
To implement the selected event, go to the object type in which theevent is local.
To implement another event (local only), select it and chooseImplement selected event.
If you want to extend the object type, choose Extend object type
. A new event is created.
Then choose Continue.