Due to the nature of this bug, this time without a demo project 
This bug crashes and sometimes destroys whole project + it gives false warnings. How to reproduce on a new project:
- Create blueprint “ClassA”, then create a child of this class named “ChildOfClassA”.
- Place both blueprints in scene
- In ClassA, in BeginPlay, add self → Cast to ChildOfClassA and click Compile. It will throw false warning:
“'Child Of Class A’ does not inherit from ‘Class A’" (Cast To ChildOfClassA would always fail).” - In ChildOfClassA, create “self” wherever you want, for example in main Event Graph.
- Click Compile, it will: a) crash and whole project will be broken - it will not open again or b) it will delete ChildOfClassA blueprint itself!
or c) it will just crash with “No minidump found for this crash.” (empty log)
If this does not work, restart the project, compile again ClassA (so the warning will show), delete “self” from ChildOfClassA, place it again and click Compile. Sometimes this bug will not fire at the first time, but restarting + recompiling always ‘worked’ for me, resulting in crash.
Update: It also seems not to fire every time - if so, try compiling again ClassA, deleting “self” from ChildOfClassA and compiling it without “self” (+ do everything with ClassA and ChildOfClassA placed on scene, for example save the level as a startup one in project settings) Eventually it’ll crash.
Update 2: Here is the log after it crashed, (from Saved → Logs folder) it has some errors like “IncrementalRegisterComponents(0)” and a few more: UE Crash log - Pastebin.com - seems like the ‘error section’ starts from the “RegisterComponentWithWorld: Owner belongs to a DEADCLASS” message.
- Tested on 4.8.3