Bukkit

> [20:56:25 ERROR]: Error occurred while enabling AuthMe v2.5 (Is it up to date?)
java.lang.NoClassDefFoundError: org/bukkit/util/config/Configuration
at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.8.0_101]
at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[?:1.8.0_101]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) ~[?:1.8.0_101]
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) ~[?:1.8.0_101]
at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[?:1.8.0_101]
at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[?:1.8.0_101]
at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[?:1.8.0_101]
at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_101]
at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[?:1.8.0_101]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.java.JavaPluginLoader.getClassByName(JavaPluginLoader.java:191) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:97) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_101]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_101]
at uk.org.whoami.authme.AuthMe.onEnable(AuthMe.java:60) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:264) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:402) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.craftbukkit.v1_12_R1.CraftServer.enablePlugin(CraftServer.java:377) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.craftbukkit.v1_12_R1.CraftServer.enablePlugins(CraftServer.java:327) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at net.minecraft.server.v1_12_R1.MinecraftServer.t(MinecraftServer.java:421) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at net.minecraft.server.v1_12_R1.MinecraftServer.l(MinecraftServer.java:382) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at net.minecraft.server.v1_12_R1.MinecraftServer.a(MinecraftServer.java:337) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:272) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:544) [spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_101]
Caused by: java.lang.ClassNotFoundException: org.bukkit.util.config.Configuration
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:91) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot-1.12.jar:git-Spigot-cd6ba67-2a2d6d6]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_101]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_1

Hello there nik3214! This problem is happening because you use an a unsupported version of the Plugin. Please check if your server version is up to date and if your AuthMe Plugin is the same version as your server. I Hope I Helped you.

Have a nice day - Thegamesbg.