WorldPortal Error

[World Portal] Enabling World Portal v0.2.6
2013-08-05 09:37:46 [SEVERE] Error occurred while enabling World Portal v0.2.6 (Is it up to date?)
ru.tehkode.permissions.exceptions.PermissionsNotAvailable: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
	at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:194)
	at me.timvisee.WorldPortal.WorldPortal.setupPermissions(WorldPortal.java:125)
	at me.timvisee.WorldPortal.WorldPortal.onEnable(WorldPortal.java:101)
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
	at org.bukkit.craftbukkit.v1_6_R2.CraftServer.loadPlugin(CraftServer.java:282)
	at org.bukkit.craftbukkit.v1_6_R2.CraftServer.enablePlugins(CraftServer.java:264)
	at net.minecraft.server.v1_6_R2.MinecraftServer.l(MinecraftServer.java:313)
	at net.minecraft.server.v1_6_R2.MinecraftServer.f(MinecraftServer.java:290)
	at net.minecraft.server.v1_6_R2.MinecraftServer.a(MinecraftServer.java:250)
	at net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:151)
	at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:391)
	at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)