org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: net/minecraft/server/v1_7_R4/PlayerInventory
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-1530]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot.jar:git-Spigot-1530]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot.jar:git-Spigot-1530]
	at org.bukkit.craftbukkit.v1_7_R3.CraftServer.loadPlugins(CraftServer.java:369) [spigot.jar:git-Spigot-1530]
	at org.bukkit.craftbukkit.v1_7_R3.CraftServer.reload(CraftServer.java:864) [spigot.jar:git-Spigot-1530]
	at org.bukkit.Bukkit.reload(Bukkit.java:301) [spigot.jar:git-Spigot-1530]
	at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:24) [spigot.jar:git-Spigot-1530]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:180) [spigot.jar:git-Spigot-1530]
	at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCommand(CraftServer.java:767) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.PlayerConnection.handleCommand(PlayerConnection.java:1014) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:845) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:184) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.ServerConnection.c(ServerConnection.java:81) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:720) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:283) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:583) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:489) [spigot.jar:git-Spigot-1530]
	at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1530]
Caused by: java.lang.NoClassDefFoundError: net/minecraft/server/v1_7_R4/PlayerInventory
	at com.massivecraft.massivecore.MassiveCore.getMassiveCoreGsonBuilder(MassiveCore.java:85) ~[?:?]
	at com.massivecraft.massivecore.MassiveCore.<clinit>(MassiveCore.java:70) ~[?:?]
	at java.lang.Class.forName0(Native Method) ~[?:1.7.0_55]
	at java.lang.Class.forName(Class.java:270) ~[?:1.7.0_55]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:40) ~[spigot.jar:git-Spigot-1530]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:127) ~[spigot.jar:git-Spigot-1530]
	... 19 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_7_R4.PlayerInventory
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:67) ~[spigot.jar:git-Spigot-1530]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[spigot.jar:git-Spigot-1530]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425) ~[?:1.7.0_55]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ~[?:1.7.0_55]
	at com.massivecraft.massivecore.MassiveCore.getMassiveCoreGsonBuilder(MassiveCore.java:85) ~[?:?]
	at com.massivecraft.massivecore.MassiveCore.<clinit>(MassiveCore.java:70) ~[?:?]
	at java.lang.Class.forName0(Native Method) ~[?:1.7.0_55]
	at java.lang.Class.forName(Class.java:270) ~[?:1.7.0_55]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:40) ~[spigot.jar:git-Spigot-1530]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:127) ~[spigot.jar:git-Spigot-1530]
	... 19 more