Ripperdoc in Longshore Stacks.

[Salinga]

I can't get out because the door won't open. The conversation menu prevents the option to open the door from appearing.

[Nooneyouknow]

Had the same issue, and turns out there's two solutions - If you pick the dialogue option while he's talking you can mash the open button, and the second is NPCs path in every few minutes or so and that will free you.