muzliAnnounce bug

[SEVERE] Could not load 'plugins/MuezliAnnouncer.jar' in folder 'plugins'

org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: me/ScottSpittle/MuezliAutoItemBarReload/main : Unsupported major.minor version 51.0

  at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:184)

  at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)

  at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)

  at org.bukkit.craftbukkit.v1_6_R2.CraftServer.loadPlugins(CraftServer.java:239)

  at org.bukkit.craftbukkit.v1_6_R2.CraftServer.reload(CraftServer.java:603)

  at org.bukkit.Bukkit.reload(Bukkit.java:275)

  at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:23)

  at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)

  at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:523)

  at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:964)

  at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:882)

  at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:839)

  at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)

  at net.minecraft.server.v1_6_R2.NetworkManager.b(NetworkManager.java:296)

  at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)

  at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)

  at net.minecraft.server.v1_6_R2.DedicatedServerConnection.b(SourceFile:30)

  at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:590)

  at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:226)

  at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:486)

  at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:419)

  at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)

Caused by: java.lang.UnsupportedClassVersionError: me/ScottSpittle/MuezliAutoItemBarReload/main : Unsupported major.minor version 51.0

  at java.lang.ClassLoader.defineClass1(Native Method)

  at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)

  at java.lang.ClassLoader.defineClass(ClassLoader.java:615)

  at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)

  at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)

  at java.net.URLClassLoader.access$000(URLClassLoader.java:58)

  at java.net.URLClassLoader$1.run(URLClassLoader.java:197)

  at java.security.AccessController.doPrivileged(Native Method)

  at java.net.URLClassLoader.findClass(URLClassLoader.java:190)

  at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:80)

  at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)

  at java.lang.ClassLoader.loadClass(ClassLoader.java:306)

  at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

  at java.lang.Class.forName0(Native Method)

  at java.lang.Class.forName(Class.java:247)

  at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:173)

  ... 21 more