[MC-65381] Server 14w31a crashing

The server only crashes when there is people playing on it, the error can be found in the txt files attached.

Description: Ticking entity

java.lang.NullPointerException: Ticking entity
	at aay.l(SourceFile:186)
	at aay.k(SourceFile:155)
	at xl.bE(SourceFile:450)
	at xk.l(SourceFile:1430)
	at xl.l(SourceFile:316)
	at wn.l(SourceFile:126)
	at abr.l(SourceFile:38)
	at abs.l(SourceFile:58)
	at xk.j(SourceFile:1298)