[Bukkit] Fehlermeldung bei Essentials

Hii,

habe zwar in google gesucht, aber nichts gefunde
beim Server kommt folgende Fehlermeldung:

Code:

2013-01-16 18:42:49 [WARNING] [Essentials] Task #1700 for Essentials v2.9.6 generated an exception
java.lang.NoClassDefFoundError: org/anjocaido/groupmanager/dataholder/worlds/WorldsHolder
	at com.earth2me.essentials.perm.GroupManagerHandler.getHandler(GroupManagerHandler.java:105)
	at com.earth2me.essentials.perm.GroupManagerHandler.hasPermission(GroupManagerHandler.java:68)
	at com.earth2me.essentials.perm.PermissionsHandler.hasPermission(PermissionsHandler.java:75)
	at com.earth2me.essentials.User.isAuthorizedCheck(User.java:89)
	at com.earth2me.essentials.User.isAuthorized(User.java:66)
	at com.earth2me.essentials.User.checkActivity(User.java:572)
	at com.earth2me.essentials.EssentialsTimer.run(EssentialsTimer.java:49)
	at org.bukkit.craftbukkit.v1_4_6.scheduler.CraftTask.run(CraftTask.java:53)
	at org.bukkit.craftbukkit.v1_4_6.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345)
	at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:530)
	at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224)
	at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494)
	at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427)
	at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849)

Freue mich auf Antworten.