ChestMaster error log

[06:27:29] [Server thread/INFO]: Phyx issued server command: /chest
[06:27:29] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'chest' in plugin ChestMaster v1.2
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at org.bukkit.craftbukkit.v1_8_R1.CraftServer.dispatchCommand(CraftServer.java:646) ~[spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.PlayerConnection.handleCommand(PlayerConnection.java:1115) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java:950) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java:26) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(PacketPlayInChat.java:53) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_25]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_25]
	at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:683) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:316) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:623) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:526) [spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_25]
Caused by: java.lang.NoSuchMethodError: com.earth2me.essentials.Essentials.getItemDb()Lcom/earth2me/essentials/ItemDb;
	at net.vexgames.chestmaster.PegarIS.Pegar(PegarIS.java:15) ~[?:?]
	at net.vexgames.chestmaster.Main.StringToInventory(Main.java:193) ~[?:?]
	at net.vexgames.chestmaster.Main.open(Main.java:100) ~[?:?]
	at net.vexgames.chestmaster.Main.onCommand(Main.java:70) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-BT27.jar:git-Spigot-d0d1d87-bc03b6f]
	... 14 more