CTDs are not caused by GSX

[virtuali]

As confirmed by Microsoft Community Manager on the Flight Simulator forum, MSFS user started to experience an abnormal frequency of crashes starting last Friday, the 19th.

https://forums.flightsimulator.com/t/constant-ctd-every-flight-now-ntdll-dll/537543/618

Since GSX came out not even 24 hours before, many users (and reviewers) initially assumed the problem could have been caused by it, since it was the last thing they installed.

However, it was just a most unfortunate coincidence, which we couldn't possibly foresee, considering GSX was out for less than a day, but before the problem started. While the above thread on Microsoft support forum grew, more and more evidence came out the problem couldn't possibly be caused by GSX, because there were hundreds of users reporting the same CTDs, and they never had GSX installed. And many users who also had GSX installed, still getting CTDs even after uninstalling it. Lots of users had crashes without a single add-on.

A first suggested solution was to turn off online data services in the sim, which worked for many, but of course results in a heavily reduced graphic quality and features, since photogrammetry and/or Bing data, real weather data and live traffic would be missing.

The most current suggestion from Microsoft, is following this procedure:

- Manually run Windows Update (Start → Check for updates) and install any available updates. (Note: there may be no updates available)

- Perform a full restart of your PC (even if there were no updates detected in Step 1)

- After rebooting, launch Microsoft Flight Simulator and test if you still get the ntdll.dll crash.

[jack153]

hello you have already said cdt's are not dependent on gsx and therefore my question what they trigger in conjunction with gsx?
is there already experience what msfs2020 crashes ?

how to fix the problem?

I had read this with the update of windos what I have also duch led

are there known problems with win 11

[virtuali]

hello you have already said cdt's are not dependent on gsx and therefore my question what they trigger in conjunction with gsx?

Have you read the previous post and, most importantly, the Microsoft support forum ?

CTDs will happen regardless if you have GSX or not, and are fixed in several ways, either by disabling the online data, or following the above procedure of checking for updates and Restart the PC.

[jack153]

yes as I said I had tried this with the update and I'm not saying that gsx is to blame just trying to get information to prevent CTD's and am open to suggestions for solutions

[virtuali]

just trying to get information to prevent CTD's and am open to suggestions for solutions

In the first post I linked the Microsoft forum and the current suggestion from Microsoft.

[GruenePizza]

Hello, I mean, even if the title of this forum said something different, Couatl is currently doing CTDs for me.
Is there some kind of log file that Couple generates?

[NNunumete]

MSFS support just told me that Coatl does cause my CTD's.

[virtuali]

MSFS support just told me that Coatl does cause my CTD's.

That kind of Microsoft support is very clearly some low-level guy that has no idea how Couatl or even Windows protected mode works, he's only trained to tell you to check the Event Viewer and he's doing the same assumption that "just" because you have an event there, it "must" be the cause.

I'm sure you also have a Flightsimulator.exe Event there so, under that reasoning, it "must" be the "cause", because it's there in the Event viewer.

But the difference is, while Flightsimulator.exe surely can (and does) crash on its own, Couatl64_MSFS.EXE, as an external .EXE, CANNOT crash the sim but, instead, can be affected by the simulator crashing on its own, because it will disconnect abruptly without sending a proper closing signal, so we can't always do the required memory clean up that native win64 apps must do on exit, so you also see the Couatl .exe in the Event viewer, but it was the victim of Flightsimulator.exe crashing, not the cause.

[NNunumete]

Update:
MSFS support responded with:
“I believe what is occurring is you are just overloading your PC with additional software / mods, thus leading to the MSFS crash. We see this quite often with GSX Pro in particular.”
Doesn’t really help me further….

[virtuali]

MSFS support responded with:
“I believe what is occurring is you are just overloading your PC with additional software / mods, thus leading to the MSFS crash. We see this quite often with GSX Pro in particular.”

This reply just confirms what I guessed:

They really have no idea why MSFS crashed, so they provided a very generic reply saying the sim is just overloaded, and tied this to GSX Pro, not because they know it's the cause, just because the program is quite popular, so they are getting a number of reports which is purely based on the fact there are many using GSX and several might have been misled by the Event viewer that Couatl was the "cause" of the crash, when it fact was the victim. I agree to a casual inspection.

This might seem reasonable, so many users reporting crashes in general and providing MS support with an Event viewer, are the reasons triggering that reply from MS support.

Now, it is possible that, rather than GSX/Couatl crashing the sim, the Navdata API (which is part of the sim) might have crashed itself, just because GSX made a call to it. This has been acknowledged in the SU13 release notes:

https://forums.flightsimulator.com/t/release-notes-sim-update-13-1-34-16-0-available-now/610338
 

Requesting some data using the NavData API shouldn’t freeze the sim anymore

This shows that it was likely, until SU13, that calling into the Navdata API could freeze/crash the sim, and of course GSX requires the Navdata to work so, it is possible that not ALL known issues with it have been fixed, and this might also depend on which Navdata is used. And these bugs in the Navdata API (which is part of the sim and only MS/Asobo can fix), might have been the very reasons why MS support has accumulated some kind of history about "GSX Pro crashes", when in fact they were bugs in the sim which weren't fixed until SU13, and we are not sure if there are still issues left, that is not all bugs in the Navdata API has been fixed.

To provide for this eventuality, we added a new option in the GSX Settings to Disable GSX in Cruise.

Normally, while in flight, GSX makes a call to the Navdata API when you open its menu in flight, to get a list of the nearby airports and allow you to pre-select a gate before landing.  Enabling this option will stop any communication with the Navdata API unless you are below 10k feet and are flying 250kts or slower so, even if you open the GSX menu during in flight accidentally, with GSX disabled, it won't do anything.

Also, enabling that option might help you with troubleshooting: if you are still getting a crash in flight, and you were flying over 10k feet or faster than 250 kts, you can be 100% sure it wasn't GSX.

[NNunumete]

Once again, thanks for the explanation.
I guess I just have to deal with it then, MSFS will only help me when the simulator is vanilla. But of course, there is no fun in flying vanilla...

[virtuali]

I guess I just have to deal with it then, MSFS will only help me when the simulator is vanilla. But of course, there is no fun in flying vanilla...

I doubt you'll get any help from MS, add-ons are just too many for any kind of support to deal with those. But you can try some of my suggestions:

- If you crashes happens in flight, do you notice any difference if you check the option to disable GSX in cruise ?

- If you have 3rd party Navdata installed, do you notice any difference by removing it ?

[GruenePizza]

Ok, I feel guilty writing this after MSFS support wrote to me several times that the simulator crashed because of GSX. However, that wasn't true, the problem was that a driver for my Rudder pedals was arguing with the Windows defender.

Anyway, thank you and have a nice day! 

[virtuali]

Ok, I feel guilty writing this after MSFS support wrote to me several times that the simulator crashed because of GSX. However, that wasn't true, the problem was that a driver for my Rudder pedals was arguing with the Windows defender.

Feel guilty? You should be proud of yourself for taking the time to come here to write that. Most of those coming here reporting CTDs "caused by GSX", rarely come back saying it wasn't GSX after all, which is what almost invariably turns out to be.

I had an email exchange with a user that was 100% "sure" his crashes were "caused by GSX", then he came back and said he fixed it by using the standard Windows fixing routines of Type: sfc /scannow, Dism.exe /online /cleanup-image /restorehealth and reboot. This clearly proved, again, it wasn't GSX, but his Windows install which had problems, and after the fix everything worked.