[10:44:43] [Server thread/INFO]: [Autorank] Enabling Autorank v${project.version}
[10:44:43] [Server thread/INFO]: [Autorank] Simple config file loaded
[10:44:43] [Server thread/INFO]: [Autorank] Advanced config file loaded
[10:44:43] [Server thread/INFO]: [Autorank] New playerdata.yml file loaded. AR can keep track of player progress now!
[10:44:43] [Server thread/INFO]: [Autorank] Interval check every 6 minutes.
[10:44:43] [Server thread/INFO]: [Autorank] Data file loaded
[10:44:43] [Server thread/INFO]: [Autorank] Essentials was found! AFK integration can be used.
[10:44:43] [Server thread/INFO]: [Autorank] Vault found and hooked!
[10:44:43] [Server thread/ERROR]: Error occurred while enabling Autorank v${project.version} (Is it up to date?)
java.lang.NoClassDefFoundError: com/gmail/nossr50/api/exceptions/InvalidSkillException
at me.armar.plugins.autorank.hooks.DependencyManager.(DependencyManager.java:38) ~[?:?]
at me.armar.plugins.autorank.Autorank.onEnable(Autorank.java:150) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:250) ~[spigot.jar:git-Spigot-1330]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:350) [spigot.jar:git-Spigot-1330]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:390) [spigot.jar:git-Spigot-1330]
at me.Incomprehendable.WorldPlugins.FakePluginManager.enablePlugin(FakePluginManager.java:238) [PerWorldPlugins.jar:?]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugin(CraftServer.java:460) [spigot.jar:git-Spigot-1330]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.enablePlugins(CraftServer.java:380) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.MinecraftServer.m(MinecraftServer.java:348) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.MinecraftServer.g(MinecraftServer.java:325) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.MinecraftServer.a(MinecraftServer.java:281) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.java:186) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:437) [spigot.jar:git-Spigot-1330]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot.jar:git-Spigot-1330]
Caused by: java.lang.ClassNotFoundException: com.gmail.nossr50.api.exceptions.InvalidSkillException
at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_51]
at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_51]
at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_51]
at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.7.0_51]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:77) ~[spigot.jar:git-Spigot-1330]
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[spigot.jar:git-Spigot-1330]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_51]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_51]
... 14 more

I've already made a fix that I will upload today.