On every single one of my characters I've encountered severe bugs and I was having quite a stroke of luck on my latest until now.

A quest has broken due to a scripted door not opening. The door in question has no levers/switches and is supposed to just open at a certain point.

I've tried activate, which was the command in Oblivion, but it doesn't work. I've also tried unlock and open.

How about TCL run through the door and TCL again?

Ive had 'unlock' after clicking on the door work for these types with console commands. That's not working for you?

Try PlayGroup forward 1