Hello Eric!
Thanks for replying! I tried something similar to a new map and the engine crashed again.Specificly i attached a light component to a mesh of mine and moving it to a folder had the same effect.I also tried the same thing by attaching a particle effect which again crashed the engine.So it seems like its attaching these 2 type of objects into another that causes the crash and i dont think its mesh related because attaching a light into another led to same results.Not sure if that helps in any way but felt like letting you know.
note: Attaching a mesh into another mesh doesnt cause any problems
-Tim