[09:01:45] [Server thread/ERROR] [Sponge]: Error occurred while executing command 'mpcaseshop' for source EntityPlayerMP['lLuffy'/2039, l='world', x=58.79, y=71.00, z=252.19]: unknown message type
java.lang.IllegalArgumentException: unknown message type
        at com.google.common.base.Preconditions.checkArgument(Preconditions.java:122) ~[minecraft_server.1.12.2.jar:?]
        at org.spongepowered.mod.network.SpongeIndexedMessageChannel.checkMessage(SpongeIndexedMessageChannel.java:106) ~[SpongeIndexedMessageChannel.class:1.12.2-2768-7.1.6-RC3623]
        at org.spongepowered.mod.network.SpongeIndexedMessageChannel.sendTo(SpongeIndexedMessageChannel.java:112) ~[SpongeIndexedMessageChannel.class:1.12.2-2768-7.1.6-RC3623]
        at com.mayakplay.doge.commands.CommandMPcaseshop.execute(CommandMPcaseshop.java:27) ~[CommandMPcaseshop.class:?]
        at org.spongepowered.api.command.spec.CommandSpec.process(CommandSpec.java:388) ~[CommandSpec.class:1.12.2-2768-7.1.6-RC3623]
        at org.spongepowered.api.command.dispatcher.SimpleDispatcher.process(SimpleDispatcher.java:340) ~[SimpleDispatcher.class:1.12.2-2768-7.1.6-RC3623]
        at org.spongepowered.common.command.SpongeCommandManager.process(SpongeCommandManager.java:334) [SpongeCommandManager.class:1.12.2-2768-7.1.6-RC3623]
        at net.minecraft.command.ServerCommandManager.executeCommand(SourceFile:1083) [dh.class:?]
        at net.minecraft.network.NetHandlerPlayServer.handleSlashCommand(NetHandlerPlayServer.java:960) [pa.class:?]
        at net.minecraft.network.NetHandlerPlayServer.processChatMessage(NetHandlerPlayServer.java:939) [pa.class:?]
        at net.minecraft.network.play.client.CPacketChatMessage.processPacket(SourceFile:37) [la.class:?]
        at net.minecraft.network.play.client.CPacketChatMessage.processPacket(SourceFile:9) [la.class:?]
        at org.spongepowered.common.event.tracking.phase.packet.PacketPhaseUtil.onProcessPacket(PacketPhaseUtil.java:193) [PacketPhaseUtil.class:1.12.2-2768-7.1.6-RC3623]
        at net.minecraft.network.PacketThreadUtil$1.redirect$onProcessPacket$zlh000(SourceFile:539) [hv$1.class:?]
        at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) [hv$1.class:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_201]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_201]
        at net.minecraft.util.Util.runTask(SourceFile:529) [h.class:?]
        at org.spongepowered.common.SpongeImplHooks.onUtilRunTask(SpongeImplHooks.java:301) [SpongeImplHooks.class:1.12.2-2768-7.1.6-RC3623]
        at net.minecraft.server.MinecraftServer.redirect$onRun$zjm000(MinecraftServer.java:3955) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:723) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.updateTimeLightAndEntities(DedicatedServer.java:397) [nz.class:?]
        at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:668) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_201]