Tekkit Server Crash - Java problem

[Gomo]

Hello guys,

my tekkit has recently started crashing as soon as second player joins the game. It starts up just fine, and 1 player can play normally.. but as soon as second one joins, it crashes with this error

sneak peek:

java.lang.ArrayIndexOutOfBoundsException: -1
        at java.util.ArrayList.elementData(Unknown Source)
        at java.util.ArrayList.get(Unknown Source)
        at net.minecraft.server.management.ServerConfigurationManager.func_72374_b(ServerConfigurationManager.java:1125)
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:914)
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:330)
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:777)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:659)
        at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)

http://pastebin.com/8NB15B6N

It used to work fine, and then all of the sudden after a crash caused by world edit I started having this problem. (even tho I rolled back to the old server backup)

Also, I tried many different java versions 7 and 8 (both 32 & 64 bit at same time) & also ran the server w/o plugins.. same result.

 

Edited October 12, 2015 by Gomo