Error while logging in to the server

When I go to the server wrote this error (screen)
Help how to decide ???

Could you explain better
In which this plugin to change
I'm just a beginner

Что это? Плагин?

And here on you some plugin downloaded and this error began to appear

They I have a long time and they worked

at net.minecraft.server.v1_11_R1.LoginListener.b(LoginListener.java:119) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.LoginListener.F_(LoginListener.java:57) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.NetworkManager.a(NetworkManager.java:224) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.ServerConnection.c(SourceFile:187) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:765) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:360) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:650) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:554) inecraft_server.jar:git-Bukkit-c8ff651]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
Caused by: java.lang.NoClassDefFoundError: net/md_5/bungee/api/ChatColor
at me.trevor1134.adminfun.AdminFun.onJoin(AdminFun.java:163) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_121]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:296) ~inecraft_server.jar:git-Bukkit-c8ff651]
... 14 more
[22:46:48] [Server thread/INFO]: Drago_PVP[/5.143.207.17:62422] logged in with entity id 434 at ([world]238.80533034670466, 71.87198216708953, 296.9222239615913)
[22:46:48] [Server thread/WARN]: [AuthMe] Task #74 for AuthMe v3.3.2 generated an exception
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
at fr.xephi.authme.task.MessageTask.run(MessageTask.java:30) ~[?:?]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:53) ~inecraft_server.jar:git-Bukkit-c8ff651]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:352) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:689) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:360) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:650) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:554) inecraft_server.jar:git-Bukkit-c8ff651]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
[22:46:48] [Server thread/INFO]: Drago_PVP lost connection: Disconnected
[22:46:48] [Server thread/INFO]: Drago_PVP left the game
[22:47:27] [Server thread/WARN]: [AutoMessage] Task #11 for AutoMessage v2.4.0 generated an exception
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
at com.TeamNovus.AutoMessage.Tasks.BroadcastTask.run(BroadcastTask.java:25) ~[?:?]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:53) ~inecraft_server.jar:git-Bukkit-c8ff651]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:352) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:689) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:360) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:650) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:554) inecraft_server.jar:git-Bukkit-c8ff651]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
[22:48:27] [Server thread/WARN]: [AutoMessage] Task #11 for AutoMessage v2.4.0 generated an exception
java.lang.NoSuchMethodError: org.bukkit.Server.getOnlinePlayers()[Lorg/bukkit/entity/Player;
at com.TeamNovus.AutoMessage.Tasks.BroadcastTask.run(BroadcastTask.java:25) ~[?:?]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:53) ~inecraft_server.jar:git-Bukkit-c8ff651]
at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:352) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:689) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:360) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:650) inecraft_server.jar:git-Bukkit-c8ff651]
at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:554) inecraft_server.jar:git-Bukkit-c8ff651]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
>

I decided everything but now I have such a problem.
I do not have a server that can not break blocks.
And the team does not work 'gamemode 1'