post 1.1 i used to open the door in deadlight court. now when i open it everyone turns hostile. any idea?

The locked door? I never tried to open them before doing the first assassination quest. I remember it being tagged as red, until I did the quest. 

Yes, it's changed. All it does though is to make the player to use longer route. 

it doesnt make sense. you go the other path and it isn't hostile.

Well yeah it makes sense. You're an intruder and door is guarded. It was strange guards would say like NO TOUCH but then you just open it from other direction and waltz in no problem.

If you just walked through there with no sounds of combat going on then you must belong there. That's a reasonable line of thinking for someplace that's an actual fort where any given individual probably doesn't know everyone in the fort.