运行报告
[05:42:45] [Server thread/INFO]: An unknown error occurred while attempting to perform this command
[05:42:45] [Server thread/ERROR]: Couldn't process command: 'help'
java.lang.IllegalArgumentException: Comparison method violates its general contract!
        at java.util.ComparableTimSort.mergeLo(Unknown Source) ~[?:1.8.0_51]
        at java.util.ComparableTimSort.mergeAt(Unknown Source) ~[?:1.8.0_51]
        at java.util.ComparableTimSort.mergeCollapse(Unknown Source) ~[?:1.8.0_51]
        at java.util.ComparableTimSort.sort(Unknown Source) ~[?:1.8.0_51]
        at java.util.Arrays.sort(Unknown Source) ~[?:1.8.0_51]
        at java.util.Arrays.sort(Unknown Source) ~[?:1.8.0_51]
        at java.util.ArrayList.sort(Unknown Source) ~[?:1.8.0_51]
        at java.util.Collections.sort(Unknown Source) ~[?:1.8.0_51]
        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:94) [z.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71333_ah(DedicatedServer.java:370) [lt.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:335) [lt.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
没有崩溃报告，求解。。。

求大佬帮助，没有/help其他指令记不住

有没有大佬帮帮我呀