Bukkit

What steps will reproduce the problem?
1.all command
19:06:00 CONSOLE: [INFO] Giuseppe1990 issued server command: /pm load tron
19:06:00 CONSOLE: WARN]: org.bukkit.plugin.InvalidPluginException: java.lang.IllegalArgumentException: Plugin already initialized!
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:137)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:313)
19:06:00 CONSOLE: WARN]: at co.technius.PluginManager.PluginControl.loadPlugin(PluginControl.java:289)
19:06:00 CONSOLE: WARN]: at co.technius.PluginManager.PMCommandExecutor.loadCmd(PMCommandExecutor.java:448)
19:06:00 CONSOLE: WARN]: at co.technius.PluginManager.PMCommandExecutor.onCommand(PMCommandExecutor.java:497)
19:06:00 CONSOLE: WARN]: at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
19:06:00 CONSOLE: WARN]: at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:175)
19:06:00 CONSOLE: WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:683)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:952)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:814)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:47)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457)
19:06:00 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617)
19:06:00 CONSOLE: WARN]: Caused by: java.lang.IllegalArgumentException: Plugin already initialized!
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:98)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:59)
19:06:00 CONSOLE: WARN]: at me.nextinline.tron.Core.<init>(Core.java:19)
19:06:00 CONSOLE: WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
19:06:00 CONSOLE: WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
19:06:00 CONSOLE: WARN]: at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
19:06:00 CONSOLE: WARN]: at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
19:06:00 CONSOLE: WARN]: at java.lang.Class.newInstance(Class.java:374)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:52)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:133)
19:06:00 CONSOLE: WARN]: ... 18 more
19:06:00 CONSOLE: WARN]: Caused by: java.lang.IllegalStateException: Initial initialization
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:101)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:59)
19:06:00 CONSOLE: WARN]: at me.nextinline.tron.Core.<init>(Core.java:19)
19:06:00 CONSOLE: WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
19:06:00 CONSOLE: WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
19:06:00 CONSOLE: WARN]: at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
19:06:00 CONSOLE: WARN]: at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
19:06:00 CONSOLE: WARN]: at java.lang.Class.newInstance(Class.java:374)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:52)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:133)
19:06:00 CONSOLE: WARN]: at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:313)
19:06:01 CONSOLE: WARN]: at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:236)
19:06:01 CONSOLE: WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugins(CraftServer.java:350)
19:06:01 CONSOLE: WARN]: at org.bukkit.craftbukkit.v1_7_R1.CraftServer.<init>(CraftServer.java:312)
19:06:01 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.PlayerList.<init>(PlayerList.java:63)
19:06:01 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.DedicatedPlayerList.<init>(SourceFile:14)
19:06:01 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.java:126)
19:06:01 CONSOLE: WARN]: at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:424)
19:06:01 CONSOLE: WARN]: ... 1 more