dragon age ultimate edition quest problem

I am involved in saving the queen quest in denerim in arl howe's estate. I have defeated the arl and got his key and the jailor's key, yet when i try to free rexel from the missing in action quest nothing happens, he doesn't acknowledge me and the cell door stays shut. Same with Irminric. He doesn't respond at all and no cell door opens. Is there anything to do to fix this?