Testing the newly released 1334 right now on a 1.7.10 server because I have issues with knockback permission on all older versions (1187 and 1330). Now I resetted the complete mod (by removing the FE-dirs from minecraft server and world dirs) and I'm not able to execute any area or perm commands. Something is wrong here, further tests pending...

Did FE create default files after your removal of existing ones?

Please send me a copy of your permission file(s).

The same thing is happening to me. It says you do not have permission to run this command. But I am pary of the OP group and server admin. I still can't create groups yet.
It is my first time using this since NO OTHER mod developer has this type of admin control for forge servers that are 1.7.10.
@AnrDaemon

I've put your file into a gist and indented it for readability. Please do this in the future.

Specifically, the ~/world/FEData directory.

Same issues confirmed on a clean server instance:

FEData.zip
Tail of latest.log: http://pastebin.com/raw/wYET3xUM

https://gist.github.com/83f1c896a297b01005013308fe5f1a9d

Please contact after 2:15 Pm if you need anything else. :)

OK sorry.

Sorry, been a bit busy lately. Unfortunately I switched back to 1330 and began already to set it up. I'm gonna use a redstone clock for the knockback as FE seems to be a bit glitchy, if you want to lock players inside an area. (It works great to keep players out though)

We reverted the code back to 1330 and that solved this issue.