error DC

[07:09:55 ERROR]: Could not load 'plugins/DeathChest.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: net/gogume1er/deathchest/DeathChest : Unsupported major.minor version 52.0
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.craftbukkit.v1_9_R1.CraftServer.loadPlugins(CraftServer.java:296) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.craftbukkit.v1_9_R1.CraftServer.reload(CraftServer.java:743) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.Bukkit.reload(Bukkit.java:539) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:25) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.craftbukkit.v1_9_R1.CraftServer.dispatchCommand(CraftServer.java:645) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.craftbukkit.v1_9_R1.CraftServer.dispatchServerCommand(CraftServer.java:631) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at net.minecraft.server.v1_9_R1.DedicatedServer.aL(DedicatedServer.java:438) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at net.minecraft.server.v1_9_R1.DedicatedServer.D(DedicatedServer.java:401) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at net.minecraft.server.v1_9_R1.MinecraftServer.C(MinecraftServer.java:660) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:559) [spigot.jar:git-Spigot-1480adb-6247aa0]
        at java.lang.Thread.run(Thread.java:745) [?:1.7.0_95]
Caused by: java.lang.UnsupportedClassVersionError: net/gogume1er/deathchest/DeathChest : Unsupported major.minor version 52.0
        at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.7.0_95]
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800) ~[?:1.7.0_95]
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[?:1.7.0_95]
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) ~[?:1.7.0_95]
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71) ~[?:1.7.0_95]
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361) ~[?:1.7.0_95]
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355) ~[?:1.7.0_95]
        at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_95]
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354) ~[?:1.7.0_95]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425) ~[?:1.7.0_95]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ~[?:1.7.0_95]
        at java.lang.Class.forName0(Native Method) ~[?:1.7.0_95]
        at java.lang.Class.forName(Class.java:278) ~[?:1.7.0_95]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-1480adb-6247aa0]
        ... 14 more