If a player change the command in a command block it kicks the player.
Error code:
2013-02-06 21:00:57 [WARNING] Failed to handle packet for TEDDYKILLER007/81.217.190.77: java.lang.StringIndexOutOfBoundsException: String index out of range: 0
java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:686)
at OEntityPlayerMP.a(OEntityPlayerMP.java:761)
at ONetServerHandler.a(ONetServerHandler.java:1010)
at OPacket250CustomPayload.a(SourceFile:59)
at OTcpConnection.b(SourceFile:349)
at ONetServerHandler.d(ONetServerHandler.java:44)
at ONetworkListenThread.b(SourceFile:39)
at ODedicatedServerListenThread.b(SourceFile:30)
at OMinecraftServer.r(OMinecraftServer.java:474)
at ODedicatedServer.r(SourceFile:248)
at OMinecraftServer.q(OMinecraftServer.java:384)
at OMinecraftServer.run(OMinecraftServer.java:323)
at OThreadMinecraftServer.run(SourceFile:849)
If a player change the command in a command block it kicks the player.
Error code: