23:05:48 [SEVERE] Could not load 'plugins/SkylandsPlus.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: com/comphenix/protocol/events/PacketListener
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:184)
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)
        at org.bukkit.craftbukkit.v1_5_R1.CraftServer.loadPlugins(CraftServer.java:239)
        at org.bukkit.craftbukkit.v1_5_R1.CraftServer.<init>(CraftServer.java:217)
        at net.minecraft.server.v1_5_R1.PlayerList.<init>(PlayerList.java:55)
        at net.minecraft.server.v1_5_R1.DedicatedPlayerList.<init>(SourceFile:11)
        at net.minecraft.server.v1_5_R1.DedicatedServer.init(DedicatedServer.java:105)
        at net.minecraft.server.v1_5_R1.MinecraftServer.run(MinecraftServer.java:381)
        at net.minecraft.server.v1_5_R1.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.NoClassDefFoundError: com/comphenix/protocol/events/PacketListener
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:173)
        ... 9 more
Caused by: java.lang.ClassNotFoundException: com.comphenix.protocol.events.PacketListener
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:80)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 12 more