I am absolutely bored to death running around trying to figure out how to get those final 16 meters through the door with the keypad on it. This is in the first 10 minutes of playing and it's absolutely stupid. I've shot everyone who could be shot and I'm running up and down along a tall concrete barbed wire wall unable to get to the destination point. . . I'm supposed to "go north through the camp" only there is nowhere else to go.
Edit: blah blah blah forget it i got it . . .
OK OK I went back to previous Ckpoint and this time when I got to the part and approached the keypad I got the X prompt . . . and am now going to continue on with the campaign.
So I got past it.

From the location head to the shower chamber to the right of you( tents) .....You have to take out 2 guards and then enter the shower at the rear ...you should see a keypad that allows access to the next level.

Obviously he has never utilized the cloak function to its full potential lol it makes supersoldier difficulty seem much easier