null
org.bukkit.command.CommandException: Cannot execute command 'gamemode' in plugin Essentials vTeamCity - plugin is disabled.
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:36) ~[spigot.jar:git-Spigot-e8ded36-acbc348]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-e8ded36-acbc348]
	at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:648) ~[spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1401) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1236) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_191]
	at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot.jar:git-Spigot-e8ded36-acbc348]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]