I know this is an old topic, but I have been having the same issue for the past three days after a fresh reinstall of windows 10. I was also convinced it was Fs2crew as whenever I would do a flight I would not get any CTD. I also had stable 50FPS and not many addons (p3dV4 with fslabs A320).

Finally I figured out the issue, I was setting up spech recognition and realized that whenever I speak all of a sudden, the program/window closes or crashes. Also the quality of training was horrible, it never captures what I say and have to repeat each sentence 3 times. Also, I realized the CTD (Api.dll) crash would happen when I gave the PM a command with my "Assertive Pilot Tone" 😂

So I went to check the driver from device manager but it was saying everything was up to date, until I went to to the Asus Driver website (MAximus Hero VII), and realized that the correct driver wasn't installed for the Audio, once installed, I got the Asus SupremeFX and sonic radar program, I replugeed my headset but this time chose the mic as "Line" and bam, did speech recongition and voice training with no issues and did a flight. Smooth like butter!

I wanted to share for anyone who is suffering!

Will report any more CTD soon related to this issue.

Glad you got it sorted 😉