Bukkit

Describe to us the issue that you're having:
Whenever I run any of the commands in the /permission tree (/permission reload/save/examplefiles/backup) it throws the "An internal error occurred while attempting to perform this command.

Which steps will reproduce this problem?:
1)  /permissions reload
2)  /permissions save
3)  /permissions examplefiles
4)  /permissions backup
....

Do you have an error log of what happened?

27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:187) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.plugin.SimplePluginManager.subscribeToPermission(SimplePluginManager.java:654) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at java.util.WeakHashMap.put(WeakHashMap.java:449) ~[?:1.8.0_60]
27.09 16:34:50 [Server] INFO at java.util.WeakHashMap.hash(WeakHashMap.java:298) ~[?:1.8.0_60]
27.09 16:34:50 [Server] INFO Caused by: java.lang.StackOverflowError
27.09 16:34:50 [Server] INFO at java.lang.Thread.run(Thread.java:745) [?:1.8.0_60]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:540) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:632) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:335) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:676) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.SystemUtils.a(SystemUtils.java:19) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_60]
27.09 16:34:50 [Server] INFO at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_60]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(SourceFile:9) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(SourceFile:37) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:939) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1079) [custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:621) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:140) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[custom.jar:git-Bukkit-1880a9c]
27.09 16:34:50 [Server] INFO org.bukkit.command.CommandException: Unhandled exception executing command 'permissions' in plugin bPermissions v2.12
27.09 16:34:50 [Server] ERROR null

Which version of bPermissions are you using?: (Please don't say "latest"!!!)
2.12
Which version of CraftBukkit?: (Please don't say "latest"!!!)
Craftbukkit 1.8.8
Which OS?
Windows 7
Any other information we may need (plugins, configs, etc):

Whenever I try to do /world it tells me "[bpermissions] No world selected."
It doesn't give me a list of worlds to choose from either.

Please fill out this form properly! Failing to do so may result in your ticket being marked invalid.

Try v2.10.9m , as new bpermisions versions are usually pretty unstable and not reliable.

Id that does not fix the problem, check your group inheritances and syntaxes