I found these instances when engine stops unexpectedly.
Engine of Dahar propeller stops before taking off after sits for a while on the runway in the beginning.
Engine of any aircraft may stop if I put on active pause for a while and resume.
Engine of 787 stops in mid flight and then resumes by itself after a while.
I use outside view. Not sure if outside view causes this.
Anyone sees this too?
It’s likely because you have the mixture control mapped to your controller. While those planes don’t use it, if it’s mapped, it will shut down your engine.
I had a similar problem. After trying to find a solution I had to reinstall MSFS. Now what happens is planes rudder turns to the left when I connect the AP. 
Crunchmeister71 said it right. I unmap the mixture from the controller and the plane no longer stalls
Of course, it did. Why would you want a realistic simulator that allows you to map a real setting? Piece of junk.
I am having a similar problem with a Cessna 172 and I already removed controller references to Mixture. Any other suggestions? I am running the latest code on a powerful PC with excellent frame rates.
I have a similar situation. As a beginner I start flying Cessna 152. Each time after landing, and my throttle is pulled back to almost 0, the engine would stop on the runway. The on-screen message says hit ctrl+e to start engine but it no longer starts at all.
In the case of the 152 and the 172, you DO want a mixture axis mapped as those planes have those controls. If you don’t want Mixture mapped to them, then enable Auto-Mixture in the Assistance Settings.