[13:09:03] [Server thread/ERROR]: Could not load 'plugins/MergedMob-13.5.5.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: com/vk2gpz/mergedmob/a/d/a has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugins(CraftServer.java:292) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:198) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:525) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_212]
Caused by: java.lang.UnsupportedClassVersionError: com/vk2gpz/mergedmob/a/d/a has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
	at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.8.0_212]
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[?:1.8.0_212]
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[?:1.8.0_212]
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:468) ~[?:1.8.0_212]
	at java.net.URLClassLoader.access$100(URLClassLoader.java:74) ~[?:1.8.0_212]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:369) ~[?:1.8.0_212]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:363) ~[?:1.8.0_212]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_212]
	at java.net.URLClassLoader.findClass(URLClassLoader.java:362) ~[?:1.8.0_212]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_212]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_212]
	at com.vk2gpz.mergedmob.MergedMob.<clinit>(MergedMob.java:35) ~[?:?]
	at java.lang.Class.forName0(Native Method) ~[?:1.8.0_212]
	at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_212]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	... 6 more