Author Topic: couatl64_MSFS.exe causes freeze and CTD to MSFS w PMDG737  (Read 551 times)

Sandman161

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couatl64_MSFS.exe causes freeze and CTD to MSFS w PMDG737
« on: March 01, 2024, 01:08:30 am »
I have these predictable CTD's in MSFS when starting a PMDG737. Deactivating GSX helps. Windows crash reports always mentions couatl64_MSFS.exe and ntdll.dll as its culprits. How is that? Ah yes, I always start couatl64_MSFS.exe as Administrator.

virtuali

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Re: couatl64_MSFS.exe causes freeze and CTD to MSFS w PMDG737
« Reply #1 on: March 01, 2024, 10:46:47 am »
As explained so many times, Couatl cannot crash the sim.

An external .EXE cannot crash another .EXE, this is something basic about how the Windows OS works, an .EXE don't have any access to the memory space of another .EXE, unless it attached itself to it posing as a Debugger, and Couatl doesn't do anything like that.

What is possible is the opposite. If the sim crashes for other reasons, it will MADE Couatl crash, because in order to exit cleanly, Couatl needs to receive a specific command via Simconnect the sim has quit. If the sim crashes abruptly, it won't send the normal quit message to it, which would trigger some extra memory cleanup Couatl must do on itself, which if not done, will result in Couatl crashing. Not that this matters much after the sim crashed because Windows itself will clean up the memory.

That's why you see the event related to Couatl.exe in the Event Viewer: it was made to crash because the sim crashed for other reasons, so you can be easily misled thinking Couatl was the cause, but it's not. It cannot, because as a regular .EXE, it doesn't have any way to make the sim crash. But the sim can crash it.

Sandman161

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Re: couatl64_MSFS.exe causes freeze and CTD to MSFS w PMDG737
« Reply #2 on: March 01, 2024, 01:07:30 pm »
Hi Virtuali,

My bad, I really really like the way you explained the manner of working of couatl.exe to me. In a way it reassures me a bit. Not GSX but look for something else which is causing these ctd and freezes. Already have a ticket running at PMDG aswell.  Thanks again for this elaborate explanation.

Regards
Martin Graeff