''Exception Ticking World'' MC Crash

Everytime (well... ALMOST) that I make a Superflat world in Creative, Hardcore and Survival... my games freezes and some seconds later my Minecraft... CRASHES. (The biggest part of Crashes are in the Original Superflat, Tunnelers Dream (Original and Customized) and Snowy Kingdom)
I get annoyed with this crash... so if it's possible, can you fix this please? I Attached 2 of the 5 crashes... (The other 3 were not in the Crash Reports folder)

_joacovalle