Solved Error on Spigot 1.8.8

I have the Following error in my Console

Code (Text):

 Spieler • soos_snens » wieviel sind enderperlen wert
[11:03:51 FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException: Index: 53, Size: 45
        at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_171]
        at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_171]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:45) [spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]
Caused by: java.lang.IndexOutOfBoundsException: Index: 53, Size: 45
        at java.util.ArrayList.rangeCheck(ArrayList.java:657) ~[?:1.8.0_171]
        at java.util.ArrayList.get(ArrayList.java:433) ~[?:1.8.0_171]
        at net.minecraft.server.v1_8_R3.Container.getSlot(Container.java:109) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1668) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_171]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_171]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) ~[spigot-cb1.jar:git-Spigot-21fe707-e1ebe52]
        ... 5 more
 

But it is not a Plugin Error Can someone give me more Informations about this error?

 

Thanks Yes iam using Protocol Lib

 

And Via Version

 

Thanks for the Informations. I will report this

 

Its from ViaVersion or Protocol lib. Use the right version for your server. And try to update your plugins.

 

For me, i see no sense in this hacky viaversion. Dont use it. Only allow clients with a version matching your servers one.