Crash report #1: (Crashed by World.a) - http://pastebin.com/cGKzbYfJ
#2 (Crashed by World.getEntities()) - http://pastebin.com/k2SVpjTu

The server starts to keep crashing after I update it to 1.8.8. The cause is still unsure.

I have tried replace all command block contraptions around the map with plugins, since it seems like caused by vanilla mechanics, but the crashing won'st stop.

(I could not figure out the way to close down previous issues #1396, but that one nearly got no reply, so I update all info and created a new one)