[19:02:20] [Client thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_31]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_31]
at net.minecraft.util.Util.runTask(Util.java:23) [Util.class:?]
at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1070) [Minecraft.class:?]
at net.minecraft.client.Minecraft.run(Minecraft.java:380) [Minecraft.class:?]
at net.minecraft.client.main.Main.main(Main.java:116) [Main.class:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_31]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_31]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_31]
at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_31]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_31]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_31]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_31]
at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_31]
at net.minecraftforge.gradle.GradleStartCommon.launch(GradleStartCommon.java:97) [start/:?]
at GradleStart.main(GradleStart.java:26) [start/:?]
Caused by: java.lang.NullPointerException
at net.minecraft.client.network.NetHandlerPlayClient.handleUpdateTileEntity(NetHandlerPlayClient.java:1282) ~[NetHandlerPlayClient.class:?]
at net.minecraft.network.play.server.S35PacketUpdateTileEntity.processPacket(S35PacketUpdateTileEntity.java:55) ~[S35PacketUpdateTileEntity.class:?]
at net.minecraft.network.play.server.S35PacketUpdateTileEntity.processPacket(S35PacketUpdateTileEntity.java:12) ~[S35PacketUpdateTileEntity.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(PacketThreadUtil.java:15) ~[PacketThreadUtil$1.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_31]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_31]
at net.minecraft.util.Util.runTask(Util.java:22) ~[Util.class:?]
... 15 more

Fixed this in 36f78e4