From the first lesson, I still have the problem that whenever I move the childTurret in the TankBP viewport and recompile, the engine creates a new child which is visible in both the editor viewport and the BP viewport itself as described in the old anouncement thread by another user.
I checked my code and compared it with yours and it is literally the same but maybe I missed something. It would be nice if you could make a statement either at the beginning of the second video or in the thread about whether the UCHildActorComponent stuff is buggy in 4.11 or well, I don’t know to be honest 
I started the project in 4.11 preview 4 or whenever your first lesson aired, just for your information.
To be honest with you guys, I really appreciate what you are doing for the community and I know this must be a lot! of work, but for the future I think it would be nice if you could have an eye on the accompanying thread for further help as the other thread didn’t get a lot of attention by both of you. (Of course there was GDC etc. so nothing personal and I hope you take my opinion in a neutral way)