WardrobeGUIPlus error

11:22:21 [WARN] org.bukkit.plugin.InvalidPluginException: java.lang.ClassFormatError: Duplicate method name&signature in class file ro/Velcea123/WardrobeGUI
11:22:21 [WARN]         at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135)
11:22:21 [WARN]         at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329)
11:22:21 [WARN]         at com.rylinaux.plugman.util.PluginUtil.load(PluginUtil.java:262)
11:22:21 [WARN]         at com.rylinaux.plugman.command.LoadCommand.execute(LoadCommand.java:114)
11:22:21 [WARN]         at com.rylinaux.plugman.PlugManCommands.onCommand(PlugManCommands.java:100)
11:22:21 [WARN]         at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
11:22:21 [WARN]         at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141)
11:22:21 [WARN]         at org.bukkit.craftbukkit.v1_8_R2.CraftServer.dispatchCommand(CraftServer.java:646)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.PlayerConnection.handleCommand(PlayerConnection.java:1138)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.PlayerConnection.a(PlayerConnection.java:973)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.PacketPlayInChat.a(PacketPlayInChat.java:45)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.PacketPlayInChat.a(PacketPlayInChat.java:1)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.PlayerConnectionUtils$1.run(SourceFile:13)
11:22:21 [WARN]         at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
11:22:21 [WARN]         at java.util.concurrent.FutureTask.run(FutureTask.java:262)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.SystemUtils.a(SourceFile:60)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.MinecraftServer.A(MinecraftServer.java:710)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.DedicatedServer.A(DedicatedServer.java:368)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.MinecraftServer.z(MinecraftServer.java:651)
11:22:21 [WARN]         at net.minecraft.server.v1_8_R2.MinecraftServer.run(MinecraftServer.java:554)
11:22:21 [WARN]         at java.lang.Thread.run(Thread.java:745)
11:22:21 [WARN] Caused by: java.lang.ClassFormatError: Duplicate method name&signature in class file ro/Velcea123/WardrobeGUI
11:22:21 [WARN]         at java.lang.ClassLoader.defineClass1(Native Method)
11:22:21 [WARN]         at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
11:22:21 [WARN]         at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
11:22:21 [WARN]         at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
11:22:21 [WARN]         at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
11:22:21 [WARN]         at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
11:22:21 [WARN]         at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
11:22:21 [WARN]         at java.security.AccessController.doPrivileged(Native Method)
11:22:21 [WARN]         at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
11:22:21 [WARN]         at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101)
11:22:21 [WARN]         at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86)
11:22:21 [WARN]         at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
11:22:21 [WARN]         at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
11:22:21 [WARN]         at java.lang.Class.forName0(Native Method)
11:22:21 [WARN]         at java.lang.Class.forName(Class.java:274)
11:22:21 [WARN]         at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64)
11:22:21 [WARN]         at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131)
11:22:21 [WARN]         ... 20 more