[11:35:09] [Server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.7.0_60]
	at java.util.concurrent.FutureTask.get(FutureTask.java:188) ~[?:1.7.0_60]
	at g.a(SourceFile:46) [15w32b.jar:?]
	at net.minecraft.server.MinecraftServer.D(SourceFile:592) [15w32b.jar:?]
	at net.minecraft.server.MinecraftServer.C(SourceFile:548) [15w32b.jar:?]
	at btp.C(SourceFile:152) [15w32b.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:452) [15w32b.jar:?]
	at java.lang.Thread.run(Thread.java:745) [?:1.7.0_60]
Caused by: java.lang.NullPointerException
	at acx.a(SourceFile:122) ~[15w32b.jar:?]
	at abw.a(SourceFile:144) ~[15w32b.jar:?]
	at li.a(SourceFile:250) ~[15w32b.jar:?]
	at lo.a(SourceFile:513) ~[15w32b.jar:?]
	at jb.a(SourceFile:32) ~[15w32b.jar:?]
	at jb.a(SourceFile:9) ~[15w32b.jar:?]
	at fh$1.run(SourceFile:13) ~[15w32b.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) ~[?:1.7.0_60]
	at java.util.concurrent.FutureTask.run(FutureTask.java:262) ~[?:1.7.0_60]
	at g.a(SourceFile:45) ~[15w32b.jar:?]
	... 5 more