Mcore won't work HELP!

I have the latest java and i own a mac so could someone look at this plz
thx if u take the time for me

Last login: Wed Oct 23 17:26:20 on ttys007
Macintosh-2:~ student$ /Users/student/Desktop/bukkit/start.command ; exit;
17:26:21 [INFO] Starting minecraft server version 1.6.4
17:26:21 [INFO] Loading properties
17:26:21 [INFO] Default game type: SURVIVAL
17:26:21 [INFO] Generating keypair
17:26:21 [INFO] Starting Minecraft server on *:25565
17:26:22 [INFO] This server is running CraftBukkit version git-Bukkit-1.6.2-R1.0-3-g9532cb6-b2889jnks (MC: 1.6.4) (Implementing API version 1.6.4-R0.1-SNAPSHOT)
17:26:22 [SEVERE] Could not load 'plugins/mcore.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: com/massivecraft/mcore/MCore : 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_R3.CraftServer.loadPlugins(CraftServer.java:239)
at org.bukkit.craftbukkit.v1_6_R3.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_6_R3.PlayerList.<init>(PlayerList.java:56)
at net.minecraft.server.v1_6_R3.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_6_R3.DedicatedServer.init(DedicatedServer.java:107)
at net.minecraft.server.v1_6_R3.MinecraftServer.run(MinecraftServer.java:393)
at net.minecraft.server.v1_6_R3.ThreadServerApplication.run(SourceFile:583)
Caused by: java.lang.UnsupportedClassVersionError: com/massivecraft/mcore/MCore : 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:249)
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:173)
... 9 more
17:26:22 [INFO] [GroupManager] Loading GroupManager v2.0 (2.11.1) (Phoenix)
17:26:22 [INFO] [WorldEdit] Loading WorldEdit v5.5.8
17:26:22 [INFO] [ArrowArsenal] Loading ArrowArsenal v0.5
17:26:22 [INFO] [Vault] Loading Vault v1.2.27-b349
17:26:22 [INFO] [Multiverse-Core] Loading Multiverse-Core v2.4-b527
17:26:22 [INFO] [WorldGuard] Loading WorldGuard v5.8
17:26:22 [INFO] [Essentials] Loading Essentials v2.11.1
17:26:22 [INFO] [EssentialsProtect] Loading EssentialsProtect v2.11.1
17:26:22 [INFO] [EssentialsSpawn] Loading EssentialsSpawn v2.11.1
17:26:22 [INFO] [Multiverse-Portals] Loading Multiverse-Portals v2.4-b548
17:26:22 [INFO] [EssentialsChat] Loading EssentialsChat v2.11.1
17:26:22 [INFO] [EssentialsAntiBuild] Loading EssentialsAntiBuild v2.11.1
17:26:22 [INFO] [Vault] Enabling Vault v1.2.27-b349
17:26:22 [INFO] [Vault][Economy] Essentials Economy found: Waiting
17:26:22 [INFO] [Vault][Permission] GroupManager found: Waiting
17:26:22 [INFO] [Vault][Permission] SuperPermissions loaded as backup permission system.
17:26:22 [INFO] [Vault][Chat] GroupManager found: Waiting
17:26:22 [INFO] [Vault] Enabled Version 1.2.27-b349
17:26:22 [INFO] Preparing level "world"
17:26:22 [INFO] Preparing start region for level 0 (Seed: -2346136855191607027)
17:26:23 [INFO] Preparing spawn area: 59%
17:26:23 [INFO] ----- Bukkit Auto Updater -----
17:26:23 [INFO] It appears that you're running a Development Build, when you've specified in bukkit.yml that you prefer to run Recommended Builds.
17:26:23 [INFO] If you would like to be kept informed about new Development Build releases, it is recommended that you change 'preferred-channel' in your bukkit.yml to 'dev'.
17:26:23 [INFO] With that set, you will be told whenever a new version is available for download, so that you can always keep up to date and secure with the latest fixes.
17:26:23 [INFO] If you would like to disable this warning, simply set 'suggest-channels' to false in bukkit.yml.
17:26:23 [INFO] ----- ------------------- -----
17:26:24 [INFO] Preparing start region for level 1 (Seed: -2346136855191607027)
17:26:24 [INFO] Preparing start region for level 2 (Seed: -8462621566905932263)
17:26:24 [INFO] [GroupManager] Enabling GroupManager v2.0 (2.11.1) (Phoenix)
17:26:24 [INFO] GroupManager - INFO - World Found: world
17:26:24 [INFO] GroupManager - INFO - Superperms support enabled.
17:26:24 [INFO] GroupManager - INFO - Scheduled Data Saving is set for every 10 minutes!
17:26:24 [INFO] GroupManager - INFO - Backups will be retained for 24 hours!
17:26:24 [INFO] GroupManager version 2.0 (2.11.1) (Phoenix) is enabled!
17:26:24 [INFO] [Vault][Permission] GroupManager hooked.
17:26:24 [INFO] [Vault][Chat] GroupManager - Chat hooked.
17:26:25 [INFO] [WorldEdit] Enabling WorldEdit v5.5.8
17:26:25 [INFO] WEPIF: GroupManager detected! Using GroupManager for permissions.
17:26:25 [INFO] [ArrowArsenal] Enabling ArrowArsenal v0.5
17:26:25 [INFO] [Multiverse-Core] Enabling Multiverse-Core v2.4-b527
17:26:25 [INFO] [Multiverse-Core] - Version 2.4-b527 (API v14) Enabled - By Rigby, fernferret, lithium3141 and main--
17:26:25 [INFO] [AllPay] - Version 10.0 - hooked into Essentials Economy for Multiverse-Core v2.4-b527
17:26:25 [INFO] [Multiverse-Core] Loading World & Settings - 'world' - Env: NORMAL - Type: NORMAL & seed: -2346136855191607027
17:26:25 [INFO] [Multiverse-Core] Loading World & Settings - 'world_nether' - Env: NETHER - Type: NORMAL & seed: -2346136855191607027
17:26:25 [WARNING] [Multiverse-Core] Spawn location from world.dat file was unsafe. Adjusting...
17:26:25 [WARNING] [Multiverse-Core] Original Location: X: 0 Y: 64 Z: 0 P: 0 Y: 0
17:26:25 [SEVERE] [Multiverse-Core] New safe spawn NOT found!!!
17:26:25 [INFO] [Multiverse-Core] Loading World & Settings - 'world_the_end' - Env: THE_END - Type: NORMAL & seed: -8462621566905932263
17:26:26 [INFO] [Multiverse-Core] 3 - World(s) loaded.
17:26:26 [INFO] [WorldGuard] Enabling WorldGuard v5.8
17:26:26 [WARNING] [WorldGuard] Found option with no heading blacklist.txt for 'Deny lava buckets'
17:26:26 [WARNING] [WorldGuard] Found option with no heading blacklist.txt for 'ignore-groups=admins,owner'
17:26:26 [WARNING] [WorldGuard] Found option with no heading blacklist.txt for 'on-use=deny,tell'
17:26:26 [INFO] [WorldGuard] (world) TNT ignition is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world) Lighters are PERMITTED.
17:26:26 [INFO] [WorldGuard] (world) Lava fire is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world) Fire spread is UNRESTRICTED.
17:26:26 [INFO] [WorldGuard] Loaded configuration for world 'world'
17:26:26 [INFO] [WorldGuard] (world_nether) TNT ignition is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_nether) Lighters are PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_nether) Lava fire is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_nether) Fire spread is UNRESTRICTED.
17:26:26 [INFO] [WorldGuard] Loaded configuration for world 'world_nether'
17:26:26 [INFO] [WorldGuard] (world_the_end) TNT ignition is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_the_end) Lighters are PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_the_end) Lava fire is PERMITTED.
17:26:26 [INFO] [WorldGuard] (world_the_end) Fire spread is UNRESTRICTED.
17:26:26 [INFO] [WorldGuard] Loaded configuration for world 'world_the_end'
17:26:26 [INFO] [WorldGuard] 0 regions loaded for 'world'
17:26:26 [INFO] [WorldGuard] 0 regions loaded for 'world_nether'
17:26:26 [INFO] [WorldGuard] 0 regions loaded for 'world_the_end'
17:26:26 [INFO] [Essentials] Enabling Essentials v2.11.1
17:26:26 [INFO] [Vault][Economy] Essentials Economy hooked.
17:26:26 [INFO] Essentials: Using GroupManager based permissions.
17:26:26 [INFO] [EssentialsProtect] Enabling EssentialsProtect v2.11.1
17:26:26 [INFO] [EssentialsSpawn] Enabling EssentialsSpawn v2.11.1
17:26:26 [INFO] [Multiverse-Portals] Enabling Multiverse-Portals v2.4-b548
17:26:26 [INFO] [Multiverse-Portals] - Version 2.4-b548 Enabled - By Rigby and fernferret
17:26:26 [INFO] [Multiverse-Portals] 0 - Portals(s) loaded
17:26:26 [INFO] [EssentialsChat] Enabling EssentialsChat v2.11.1
17:26:27 [INFO] [EssentialsAntiBuild] Enabling EssentialsAntiBuild v2.11.1
17:26:27 [INFO] Server permissions file permissions.yml is empty, ignoring it
17:26:27 [INFO] Done (4.799s)! For help, type "help" or "?"
17:26:27 [INFO] GroupManager - INFO - Bukkit Permissions Updated!
>stop
17:26:30 [INFO] CONSOLE: Stopping the server..
17:26:30 [INFO] Stopping server
17:26:30 [INFO] [EssentialsAntiBuild] Disabling EssentialsAntiBuild v2.11.1
17:26:30 [INFO] [EssentialsChat] Disabling EssentialsChat v2.11.1
17:26:30 [INFO] [Multiverse-Portals] Disabling Multiverse-Portals v2.4-b548
17:26:30 [INFO] [EssentialsSpawn] Disabling EssentialsSpawn v2.11.1
17:26:30 [INFO] [EssentialsProtect] Disabling EssentialsProtect v2.11.1
17:26:30 [INFO] [Essentials] Disabling Essentials v2.11.1
17:26:30 [INFO] [Vault][Economy] Essentials Economy unhooked.
17:26:30 [INFO] [WorldGuard] Disabling WorldGuard v5.8
17:26:30 [INFO] [Multiverse-Core] Disabling Multiverse-Core v2.4-b527
17:26:30 [INFO] [Multiverse-Core] - Disabled
17:26:30 [INFO] [Vault] Disabling Vault v1.2.27-b349
17:26:30 [INFO] [ArrowArsenal] Disabling ArrowArsenal v0.5
17:26:30 [INFO] [WorldEdit] Disabling WorldEdit v5.5.8
17:26:30 [INFO] [GroupManager] Disabling GroupManager v2.0 (2.11.1) (Phoenix)
17:26:30 [INFO] GroupManager - INFO - Scheduled Data Saving is disabled!
17:26:30 [INFO] GroupManager version 2.0 (2.11.1) (Phoenix) is disabled!
17:26:30 [INFO] Saving players
17:26:30 [WARNING] DSCT: Socket closed
17:26:30 [INFO] Saving worlds
17:26:30 [INFO] Closing listening thread
17:26:30 [INFO] Saving chunks for level 'world'/Overworld
17:26:32 [INFO] Saving chunks for level 'world_nether'/Nether
17:26:32 [INFO] Saving chunks for level 'world_the_end'/The End
17:26:32 [INFO] Stopping server
17:26:32 [INFO] Saving players
17:26:32 [INFO] Saving worlds
17:26:32 [INFO] Saving chunks for level 'world'/Overworld
>logout

[Process completed]

 

Java 7 is required to run Mcore. Install java 7 and uninstall previous versions.