[15:34:43] [Netty IO #2/ERROR]: [SafeCommandBlock] Unhandled exception occured in onPacketReceiving(PacketEvent) for SafeCommandBlock
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
    at java.lang.String.substring(Unknown Source) ~[?:1.7.0_51]
    at me.KevinW1998.SafeCommandBlock.SafeCommandBlock.getRootCmd(SafeCommandBlock.java:340) ~[SafeCommandBlock.jar:?]
    at me.KevinW1998.SafeCommandBlock.SafeCommandBlock$1.onPacketReceiving(SafeCommandBlock.java:61) ~[SafeCommandBlock.jar:?]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokeReceivingListener(SortedPacketListenerList.java:114) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.SortedPacketListenerList.invokePacketRecieving(SortedPacketListenerList.java:67) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.PacketFilterManager.handlePacket(PacketFilterManager.java:614) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.PacketFilterManager.invokePacketRecieving(PacketFilterManager.java:581) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.netty.NettyProtocolInjector.packetReceived(NettyProtocolInjector.java:281) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.netty.NettyProtocolInjector.onPacketReceiving(NettyProtocolInjector.java:247) [ProtocolLib-3.3.1.jar:?]
    at com.comphenix.protocol.injector.netty.ChannelInjector.decode(ChannelInjector.java:376) [ProtocolLib-3.3.1.jar:?]
    at net.minecraft.util.io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:232) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:131) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:173) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.handler.timeout.ReadTimeoutHandler.channelRead(ReadTimeoutHandler.java:149) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:100) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:480) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:447) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:341) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at net.minecraft.util.io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-59-g6efeddf-b3074jnks]
    at java.lang.Thread.run(Unknown Source) [?:1.7.0_51]
[15:34:43] [Netty IO #2/ERROR]: Parameters:
  net.minecraft.server.v1_7_R3.PacketPlayInCustomPayload@7f75568e[
    tag=MC|AdvCdm
    length=256
    data={0,-1,-1,-1,8,0,0,0,63,0,0,0,-44,4,103,105,118,101,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
    timestamp=1399552483506
  ]