[20:43:59] [Server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException: Index: 31, Size: 0
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_161]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_161]
	at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:45) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot.jar:git-Spigot-db6de12-18fbb24]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_161]
Caused by: java.lang.IndexOutOfBoundsException: Index: 31, Size: 0
	at java.util.ArrayList.rangeCheck(ArrayList.java:657) ~[?:1.8.0_161]
	at java.util.ArrayList.get(ArrayList.java:433) ~[?:1.8.0_161]
	at net.minecraft.server.v1_8_R3.Container.getSlot(Container.java:109) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1463) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_161]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_161]
	at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
	... 5 more