error 101

Loading libraries, please wait...
[18:31:02 INFO]: Starting minecraft server version 1.8
[18:31:02 WARN]: To start the server with more ram, launch it as "java -Xmx1024M -Xms1024M -jar minecraft_server.jar"
[18:31:02 INFO]: Loading properties
[18:31:02 INFO]: Default game type: SURVIVAL
[18:31:02 INFO]: Generating keypair
[18:31:02 INFO]: Starting Minecraft server on *:40084
[18:31:02 INFO]: This server is running CraftBukkit version git-Bukkit-15e81cf (MC: 1.8) (Implementing API version 1.8-R0.1-SNAPSHOT)
[18:31:03 ERROR]: Could not load 'plugins/DennisGodFly.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: me/JordieNiels/DennisGodFly/DennisGodFly : Unsupported major.minor version 52.0
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:133) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:328) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.craftbukkit.v1_8_R1.CraftServer.loadPlugins(CraftServer.java:288) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.craftbukkit.v1_8_R1.CraftServer.<init>(CraftServer.java:250) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at net.minecraft.server.v1_8_R1.PlayerList.<init>(PlayerList.java:69) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at net.minecraft.server.v1_8_R1.DedicatedPlayerList.<init>(SourceFile:14) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at net.minecraft.server.v1_8_R1.DedicatedServer.init(DedicatedServer.java:133) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:473) [craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at java.lang.Thread.run(Thread.java:745) [?:1.7.0_79]
Caused by: java.lang.UnsupportedClassVersionError: me/JordieNiels/DennisGodFly/DennisGodFly : Unsupported major.minor version 52.0
        at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.7.0_79]
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800) ~[?:1.7.0_79]
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[?:1.7.0_79]
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) ~[?:1.7.0_79]
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71) ~[?:1.7.0_79]
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361) ~[?:1.7.0_79]
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355) ~[?:1.7.0_79]
        at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_79]
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354) ~[?:1.7.0_79]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:77) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425) ~[?:1.7.0_79]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ~[?:1.7.0_79]
        at java.lang.Class.forName0(Native Method) ~[?:1.7.0_79]
        at java.lang.Class.forName(Class.java:274) ~[?:1.7.0_79]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:40) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:129) ~[craftbukkit-1.8.jar:git-Bukkit-15e81cf]
        ... 9 more
[18:31:03 INFO]: Preparing level "world"
[18:31:03 INFO]: Preparing start region for level 0 (Seed: 6453983789500210412)
[18:31:04 INFO]: Preparing spawn area: 54%
[18:31:04 INFO]: Preparing start region for level 1 (Seed: 6453983789500210412)
[18:31:09 INFO]: Preparing spawn area: 79%
[18:31:09 INFO]: Preparing start region for level 2 (Seed: 6453983789500210412)
[18:31:09 INFO]: Server permissions file permissions.yml is empty, ignoring it
[18:31:09 INFO]: Done (6.571s)! For help, type "help" or "?"
[18:31:09 INFO]: Starting GS4 status listener
[18:31:09 INFO]: Query running on 0.0.0.0:40084
/pl