There’s an issue on the level “Blast Pit” which can cause you to have to revert to an older save or, if all saves/autosaves take place after the issue occurs you have to restart the game. In the gas (door 2) and power (door 3) rooms you’re supposed to enter the room and push the button so that one door closes and the other opens. You can push the button from outside the first door causing it to close and it can only be reopened from the button inside the room–the button outside the room doesn’t work to open the door again.
I have moved your post into a new thread. Sorry for any confusion but we’d like to keep bug reports in this forum section. Thanks!