/help error

[10:08:07] [Server thread/ERROR]: Couldn't process command
java.lang.ClassCastException: mcp.mobius.opis.commands.server.CommandTicks cannot be cast to portablejim.veinminer.server.MinerCommand
        at portablejim.veinminer.server.MinerCommand.compareTo(MinerCommand.java:398) ~[MinerCommand.class:?]
        at java.util.ComparableTimSort.binarySort(ComparableTimSort.java:232) ~[?:1.7.0_55]
        at java.util.ComparableTimSort.sort(ComparableTimSort.java:176) ~[?:1.7.0_55]
        at java.util.ComparableTimSort.sort(ComparableTimSort.java:146) ~[?:1.7.0_55]
        at java.util.Arrays.sort(Arrays.java:472) ~[?:1.7.0_55]
        at java.util.Collections.sort(Collections.java:155) ~[?:1.7.0_55]
        at net.minecraft.command.CommandHelp.func_71534_d(SourceFile:84) ~[au.class:?]
        at net.minecraft.command.CommandHelp.func_71515_b(SourceFile:38) ~[au.class:?]
        at net.minecraft.command.CommandHandler.func_71556_a(CommandHandler.java:92) [z.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_147361_d(NetHandlerPlayServer.java:731) [mx.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_147354_a(NetHandlerPlayServer.java:710) [mx.class:?]
        at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:37) [ie.class:?]
        at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:9) [ie.class:?]
        at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:197) [ef.class:?]
        at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:165) [ms.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:644) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:326) [lj.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:531) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:414) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:670) [kx.class:?]