org.bukkit.command.CommandException: Cannot execute command 'is' in plugin uSkyBlock v2.7.6-201809101626 - plugin is disabled.
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:38) ~[patched_1.13.2.jar:git-Paper-625]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:151) ~[patched_1.13.2.jar:git-Paper-625]
at org.bukkit.craftbukkit.v1_13_R2.CraftServer.dispatchCommand(CraftServer.java:734) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.PlayerConnection.handleCommand(PlayerConnection.java:1783) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1591) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:45) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:5) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.lambda$ensureMainThread$0(PlayerConnectionUtils.java:15) ~[patched_1.13.2.jar:git-Paper-625]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_192]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_192]
at net.minecraft.server.v1_13_R2.SystemUtils.a(SystemUtils.java:108) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1018) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:439) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:940) ~[patched_1.13.2.jar:git-Paper-625]
at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:837) ~[patched_1.13.2.jar:git-Paper-625]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_192]