So I've been running into that crash during cruise or descent, not always -- in certain instances and when it happens once, it will happen on the next flight with the same route/aircraft -- what may cause this?
You are being mislead by the event viewer and are assuming that, just because you see Couatl crashed, it was the cause of your MSFS crash, but it's not.
The couatl engine, as an .EXE, doesn't have ANY access to the Flightsimulator.exe process, meaning it cannot possibly cause a crash. This is granted by the OS at the lowest level, and programs that don't attach to a process like debuggers ( and Couatl surely doesn't ) and/or are not lower level services or drivers, simply cannot crash other apps.
On the other hand, when Flight simulator crashes for any other reason, it will abruptly disconnect its communication with the Couatl program, which is waiting for a proper "quit" command ( which hasn't arrived, because the sim crashed ), to exit cleanly.
So, what really happened here, is that MSFS crashed for another completely unrelated reason, and it MADE Couatl crash too, because of the unexpected disconnection, and you are being mislead assuming Couatl has something to do with it, because you are seeing it referenced in the event viewer.
As discussed in this other post:
https://www.fsdreamteam.com/forum/index.php/topic,29540.msg191735.html#msg191735If you checked the timestamps of the Event, it's likely you'll see that Flightsimulator.exe crashed BEFORE Couatl64_MSFS.exe, which means it was the simulator that made GSX crash, not the other way around.