Most people can join my server but some cant.

I have ran my own server for over a year now, and all of a sudden, I can't join while everything else goes on like normal.

What is in the log:
[16:42:17] [Server thread/INFO]: Connected players: caw232000
[16:42:41] [Server thread/INFO]: caw232000 issued server command: /gmc
[16:43:00] [Server thread/WARN]: Failed to handle packet for /**.***.***.***:*****
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
at java.util.ArrayList.rangeCheck(Unknown Source) ~[?:1.7.0_51]
at java.util.ArrayList.set(Unknown Source) ~[?:1.7.0_51]
at net.minecraft.server.v1_7_R1.RegionFile.<init>(RegionFile.java:66) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.RegionFileCache.a(SourceFile:60) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.ChunkRegionLoader.chunkExists(ChunkRegionLoader.java:43) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:102) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerChunk.<init>(PlayerChunk.java:23) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerChunkMap.a(PlayerChunkMap.java:86) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerChunkMap.b(PlayerChunkMap.java:162) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerChunkMap.movePlayer(PlayerChunkMap.java:238) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerList.d(PlayerList.java:271) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:416) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInFlying.a(SourceFile:137) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInPosition.handle(SourceFile:63) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) ~[craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit2991.jar:git-Bukkit-1.7.2-R0.2-14-g15b04d8-b2991jnks]
[16:43:00] [Server thread/INFO]: caw232000 lost connection: Internal server error
[16:43:00] [Server thread/INFO]: caw232000 left the game.
Any help would be useful!

 

Do you always type /gmc and then it crashes? Is /gmc from the plugin called GameMode Changer re-write?

If you are running version 1.0.2 of GMC, it was compiled against CraftBukkit 1.7.2-R0.3 and you are running 1.7.2-R0.2

That "might" be an issue. You can know for sure if you just don't run that command or disable the plugin temporarily or update your server to R0.3 (could be more involved this way)

LHammonds

 

/gmc (/gamemode c) is part of the essentials plugin, my server just won't let certain people log in, even if they have never used the command /gmc

 

In the example you gave, you did get connected for about 45 seconds and were able to issue a command and about 20 seconds after that cmd, the error occurs.

Can you get the exact text of the error message other players see when they try to connect to your server and then cannot?

 

caw232000
Try stuff, but if all else fails, evacuate your worlds and player data, then start with a new jar.

You said that this was "all of a sudden", do you remember anything you did immediately before this (changing the essentials config, added a plugin, changed router settings, ect.)?

 

Thanks for the help, found out that the world I was trying to load was corrupt. When I told the server to load a new world everything worked just fine! Anyone know how to fix a corrupt world?