So my APM 2.5, which was arming and which I had configured nicely only last week, now won't arm in mission planner and can't be configured. Weirdly enough, though, when I hit the connect button MAVLINK has no problem getting all of the values it needs, then shows "connected".
The only thing that's changed is the recent Mission Planner update(s). What is going on here? I can't even load firmware now because when I try the APM just disconnects.