It appears you have an outdated computer or perhaps a low end video card. I run Aerofly in maximum resolution with no worries at all. I also run X-Plane 11, an entirely different flight simulator to Aerofly. Having a full dashboard with operating gauges etc. takes care of some memory, plus there's the actual sim itself. Any low end machine is likely to have a problem running a program with so much going on.
I purchased a new computer and decent graphics card specifically to run X-Plane 11 and then there was the extra bonus of being able to max out Aerofly. I enjoy flying both sims, plus every other decent Flight Sim available. Perhaps you should update your system, or better still write to X-Plane's forum and make your complaint, because it's wasted here. Oh yes, I'd recommend you be fully awake when you do.