15.2 hangs at start after cobblegen fills chest.

[Hoburt]

I had an iron gen placed and working fine. exited and re-entered game fine until it filled the chest above. then when I tried to re-enter it would hang at %100 on the generation screen. tried in a new world. put a diamond chest down with a diamond barrel on top. exited and re-entered, world loaded but nothing generated. just skybox. Hope this helps.