Republic of Folk

perhaps I'm doing something wrong but whenever I edit the briefing.sqf for the factions in my mission and save, it reverts to the default file (IE: I need to re-enter all the information I've put in)

perhaps I'm doing something wrong? does the respective files need to move out of the F/Common folder?

That shouldnt happen. Make sure it's write protection is off.

If you are editing the briefing in a text editor outside the game, make sure you don't have it open in the editor at the same time. Save and exit it in the editor, make the changes outside the game you need to make, then load it again.
(Talking from ArmA2 experience, perhaps this is not applicable to ArmA3).