If you're reading this guide, chances are you've stumbled across a message like this:
The purpose of this guide is to demonstrate how to re-enable achievements and prevent this from happening in the future.
Why is this happening?
In DOOM 3: BFG Edition, achievements are disabled when the console is utilized. This is to prevent players from easily obtaining achievements by using cheats.
"But I didn't cheat! I never even touched the console!" Unfortunately, pressing the f12 key affects the console and triggers the achievement lock. By default, f12 is used to take screenshots using the Steam Overlay. This is a bit of a problem, meaning that once you've taken a screenshot, you've effectively altered your current session and are unable to unlock achievements.
How do I fix this?
At this point, you have a few options:
1) Restart the game and reload a previous save, possibly losing progress. 2) Save your game and re-enable achievements by disabling the console. This is usually the best option, and will save you a lot of time.
Re-enabling Achievements (Method 2)
So your screen looks like this: At this point, you're most likely pretty confused and a little ♥♥♥♥♥♥ off. Here's how to re-enable achievements without losing progress:
Click the "Accept" button.
Pause the game and make a new Savefile.
After successfully saving the game, exit to your desktop.
Navigate to \SteamApps\common\DOOM 3 BFG Edition\base
Locate the "Default.cfg" file and open it in a text editor.
Add the following line to the bottom of the file:
seta com_allowconsole 0
It should look something like this:
Save your changes and start up DOOM 3: BFG.
Load your saved game. Achievements should be working properly again.
*Take care not to hit f12 again, as this could disable achievements again. If this happens, simply save and restart the game. "seta com_allowconsole 0" will be loaded after every restart.
If you still wish to take screenshots, rebind the screenshot key to something other than f12. I'm currently using the numpad "+" key. This can be done in the Steam Overlay.