[20:11:12 FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException: Index: 49, Size: 45
        at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_131]
        at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_131]
        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(Unknown Source) [?:1.8.0_131]
Caused by: java.lang.IndexOutOfBoundsException: Index: 49, Size: 45
        at java.util.ArrayList.rangeCheck(Unknown Source) ~[?:1.8.0_131]
        at java.util.ArrayList.get(Unknown Source) ~[?:1.8.0_131]
        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:1668) ~[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(Unknown Source) ~[?:1.8.0_131]
        at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_131]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) ~[Spigot.jar:git-Spigot-db6de12-18fbb24]
        ... 5 more