Adding an Event Dispatcher to the Level Blueprint and then renaming the initial graph node within that Event Dispatcher prevents deletion from that point forward. Renaming the Event Dispatcher from the My Blueprint panel works as expected
This was reported and tested in 4.25.3 (CL-13942748). This was reproduced in 4.24.3 (CL-11590370)
Results: Event Dispatcher in the Level's Blueprint is stuck, cannot be deleted, and permanently adds the following warnings to all compilation attempts of the Level Blueprint
No delegate property found for <Renamed_Object_Name_Here>
No SignatureFunction in MulticastDelegateProperty <Event_Dispatcher_Name_Here>
Expected: To be able to delete the Event Dispatcher
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-99612 in the post.