So I got the keycard, and I need to enter the vent thats in the room to get to the other side, but my character wont climb into the vent no matter what I do. I've taken off armor, switched weapons, reloaded saves, died, dismissed companions, changed PoV, you name it. My character refuses to climb into the vent.

Did you find a solution for this? I'm having that problem too. 

Forgive me if this seems like a super obvious question, but have you crouched and then jumped into the vent?  I don't remember where the vent is positioned, but I find that for vents that are positioned high on a wall, I have to crouch first, then jump in (often after jumping on top of some other furniture).

If you've already tried that and it hasn't worked for you, could you specify what platform you're using, and what game version you're seeing on the initial game menu?

I have the same issue, cannot enter the vent. When I reported the bug to support, they were unable to recreate. So sad, I cannot continue. I am using Windows 11