I am able to engage autopilot in this levelup aircraft but it’s sure not always easy to keep a big aircraft in trim and keep your plane flying right where the flight director tells it.
It absolutely will not engage when not in straight level trimmed flight, or when flight director is off, or when any other realism check that is in there says “the real aircraft would error and exit autopilot here”.
Are there bugs in extremely odd cases? Perhaps. Almost certainly.
But with calibrated yoke or flightstick in a neutral position, and everything else right, if you still can’t get it to go, just unplug your yoke briefly once the aircraft is trimmed and flighting right at the point the flight director horizontal and vertical lines tell you it should be at, and if in that case it does engage the autopilot, then there are spurious small analog axis changes coming from your yoke, which are too small to see, causing this. I have this problem with one of my yokes and not with another.
Very few reports of “it doesn’t work” come with near enough data to know whether or not the person reporting it is doing everything this simulated aircraft wants. ANd very few try turning off the relevant realism options, to see if that “solves” their issue.
I tried many times to overcome this challenge, and just like anything in this simming thing, some of these things are tricky.
It would be cool, for example, if the mod authors output some diagnostic information to on screen displays,so that when the auto pilot fails it would say “attitude of aircraft out of required range”, or “heading incorrect” or “vertical speed out of range”.