Having Issues downloading this plugin!!!

[mastermind71]

I have downloaded the Korra.jar plugin. When I placed it in my plugins folder and ran the server the config did not show and the plugin did not function.
I am currently running on mac.
This was like server console:
[14:45:03 INFO]: Starting minecraft server version 1.7.9

[14:45:03 INFO]: Loading properties

[14:45:03 INFO]: Default game type: SURVIVAL

[14:45:03 INFO]: Generating keypair

[14:45:03 INFO]: Starting Minecraft server on *:25565

[14:45:03 INFO]: This server is running CraftBukkit version git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks (MC: 1.7.9) (Implementing API version 1.7.9-R0.3-SNAPSHOT)

[14:45:03 ERROR]: Could not load 'plugins/Korra (2).jar' in folder 'plugins'

org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: com/projectkorra/ProjectKorra/ProjectKorra : Unsupported major.minor version 51.0

at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:328) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.craftbukkit.v1_7_R3.CraftServer.loadPlugins(CraftServer.java:355) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.craftbukkit.v1_7_R3.CraftServer.<init>(CraftServer.java:317) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at net.minecraft.server.v1_7_R3.PlayerList.<init>(PlayerList.java:68) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at net.minecraft.server.v1_7_R3.DedicatedPlayerList.<init>(SourceFile:14) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at net.minecraft.server.v1_7_R3.DedicatedServer.init(DedicatedServer.java:126) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:436) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

Caused by: java.lang.UnsupportedClassVersionError: com/projectkorra/ProjectKorra/ProjectKorra : Unsupported major.minor version 51.0

at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.6.0_65]

at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637) ~[?:1.6.0_65]

at java.lang.ClassLoader.defineClass(ClassLoader.java:621) ~[?:1.6.0_65]

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) ~[?:1.6.0_65]

at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) ~[?:1.6.0_65]

at java.net.URLClassLoader.access$000(URLClassLoader.java:58) ~[?:1.6.0_65]

at java.net.URLClassLoader$1.run(URLClassLoader.java:197) ~[?:1.6.0_65]

at java.security.AccessController.doPrivileged(Native Method) ~[?:1.6.0_65]

at java.net.URLClassLoader.findClass(URLClassLoader.java:190) ~[?:1.6.0_65]

at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:77) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at java.lang.ClassLoader.loadClass(ClassLoader.java:306) ~[?:1.6.0_65]

at java.lang.ClassLoader.loadClass(ClassLoader.java:247) ~[?:1.6.0_65]

at java.lang.Class.forName0(Native Method) ~[?:1.6.0_65]

at java.lang.Class.forName(Class.java:249) ~[?:1.6.0_65]

at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:40) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:127) ~[craftbukkit.jar:git-Bukkit-1.7.9-R0.2-1-ga6e0bfd-b3095jnks]

... 9 more

[14:45:04 INFO]: Preparing level "world"

[14:45:04 INFO]: Preparing start region for level 0 (Seed: -4835490678282174561)

[14:45:04 WARN]: Could not get information about this CraftBukkit version; perhaps you are running a custom one?: IOException

[14:45:04 WARN]: Could not get latest artifact information: IOException

[14:45:04 INFO]: Preparing start region for level 1 (Seed: -4835490678282174561)

[14:45:05 INFO]: Preparing start region for level 2 (Seed: -4835490678282174561)

[14:45:05 INFO]: Server permissions file permissions.yml is empty, ignoring it

[14:45:05 INFO]: Done (1.942s)! For help, type "help" or "?"

 

[Joeri]

What version of Java do you use
What version of PK do you use
What version of bukkit/spigot do you use?

 

[kadika661]

You need to be on java 7
[do you have java 7]

 

[mastermind71]

I use 1.7.9 of bukkit. For java I use 1.6.10_65. Project Korra I use the latest recommend build.

 

[mastermind71]

I don't know how to upgrade to java 7 on mac

 

[Joeri]

I don't know how to upgrade to java 7 on mac

I don't know either, i don't run my server on my laptop/pc. Sorry