Hi,
I keep getting this error in the Console:

2012-02-19 14:10:22 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:22 [SEVERE] at org.kitteh.vanish.VanishPerms.joinVanished(VanishPerms.java:97)
2012-02-19 14:10:22 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:22)
2012-02-19 14:10:22 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
2012-02-19 14:10:22 [SEVERE] java.lang.RuntimeException: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
2012-02-19 14:10:22 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:152)
2012-02-19 14:10:22 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getUser(PermissionsEx.java:159)
2012-02-19 14:10:22 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.performCheck(PermissiblePEX.java:131)
2012-02-19 14:10:22 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:22 [SEVERE] at org.kitteh.vanish.VanishPlugin.hooksJoin(VanishPlugin.java:100)
2012-02-19 14:10:22 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:26)
2012-02-19 14:10:22 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:22 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:22 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
2012-02-19 14:10:25 [INFO] [MCBans] TeslaRex has connected!
2012-02-19 14:10:25 [INFO] TeslaRex [/66.243.248.112:50384] logged in with entity id 1670466 at ([world] 68.125, 61.0, 29.3125)
2012-02-19 14:10:26 [INFO] [C-Prisoner] ieatanime: im on the roof
2012-02-19 14:10:28 [INFO] Connection reset
2012-02-19 14:10:28 [INFO] blaird lost connection: disconnect.endOfStream
2012-02-19 14:10:28 [INFO] [MCBans] blaird has disconnected!
2012-02-19 14:10:30 [INFO] [MCBans] Tazzy369 has connected!
2012-02-19 14:10:30 [INFO] Tazzy369 [/217.42.168.2:57244] logged in with entity id 1671017 at ([vip_planet] 4968.941484110146, 75.6235057012651, 5266.692312689525)
2012-02-19 14:10:30 [SEVERE] java.lang.RuntimeException: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:152)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getUser(PermissionsEx.java:159)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.performCheck(PermissiblePEX.java:131)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:30 [SEVERE] at org.kitteh.vanish.VanishPerms.joinVanished(VanishPerms.java:97)
2012-02-19 14:10:30 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:22)
2012-02-19 14:10:30 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
2012-02-19 14:10:30 [SEVERE] java.lang.RuntimeException: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:152)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getUser(PermissionsEx.java:159)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.performCheck(PermissiblePEX.java:131)
2012-02-19 14:10:30 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:30 [SEVERE] at org.kitteh.vanish.VanishPlugin.hooksJoin(VanishPlugin.java:100)
2012-02-19 14:10:30 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:26)
2012-02-19 14:10:30 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:30 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:30 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
2012-02-19 14:10:32 [INFO] <> [C-Prisoner] heartyy: PHEW
2012-02-19 14:10:37 [INFO] <> [D-Prisoner] michael918: wheres the courtyard
2012-02-19 14:10:37 [INFO] [MCBans] ZacZac102 has connected!
2012-02-19 14:10:37 [INFO] ZacZac102 [/65.35.169.160:52700] logged in with entity id 1671633 at ([world] -62.85869957219377, 63.0, 165.36470251116862)
2012-02-19 14:10:37 [SEVERE] java.lang.RuntimeException: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:152)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getUser(PermissionsEx.java:159)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.performCheck(PermissiblePEX.java:131)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:37 [SEVERE] at org.kitteh.vanish.VanishPerms.joinVanished(VanishPerms.java:97)
2012-02-19 14:10:37 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:22)
2012-02-19 14:10:37 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)
2012-02-19 14:10:37 [SEVERE] java.lang.RuntimeException: Permissions manager is not accessable. Is the PermissionsEx plugin enabled?
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(PermissionsEx.java:152)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.PermissionsEx.getUser(PermissionsEx.java:159)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.performCheck(PermissiblePEX.java:131)
2012-02-19 14:10:37 [SEVERE] at ru.tehkode.permissions.bukkit.superperms.PermissiblePEX.hasPermission(PermissiblePEX.java:123)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.craftbukkit.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:66)
2012-02-19 14:10:37 [SEVERE] at org.kitteh.vanish.VanishPlugin.hooksJoin(VanishPlugin.java:100)
2012-02-19 14:10:37 [SEVERE] at org.kitteh.vanish.listeners.ListenPlayerJoin.onPlayerJoinEarly(ListenPlayerJoin.java:26)
2012-02-19 14:10:37 [SEVERE] at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.java.JavaPluginLoader$103.execute(JavaPluginLoader.java:1024)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:61)
2012-02-19 14:10:37 [SEVERE] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.ServerConfigurationManager.c(ServerConfigurationManager.java:131)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetLoginHandler.b(NetLoginHandler.java:121)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetLoginHandler.a(NetLoginHandler.java:40)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:61)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:537)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:435)
2012-02-19 14:10:37 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:465)

I asked around at the PEX thread first, but apparently they don't know on which side it is.

Is there any way how I could fix this?

Thanks!

This is completely a PEX issue and you should make sure they fix it, I know others are experiencing it as well.