P3D v3.3.5 CTDs (ntdll) after KDFW install

[kikigey89]

Hey guys,

In preparation for Cross the Pond on VATSIM I bought KDFW, installed it and first everything was working flawlessly.
Yesterday I started some long haul tests, just to be sure I won't expect some weird issues during CTP.
After a few hours of flight I experienced a CTD with a problem in ntdll.dll. I restarted the sim and tried again. Again a CTD after some time.
I did a lot of testing (closing apps, deactivating modules in P3D) and found out that if I delete the couatl entry from exe.xml I do not get CTDs. If I include that entry. the CTDs reappear.

I already reinstalled Addon Manager (standalone), Couatl (via Live Update) and reinstalled GSX - No success

Do you have any ideas?

Best regards,

Chris

[virtuali]

Couatl.exe, by itself, cannot cause a crash in the sim, since it's an external executable so, by definition, it doesn't have any chance to affect the simulator.

However, there's a longstanding issue in P3D, which has been reported many times to LM, that P3D is "leaking" Simconnect exceptions caused by OTHER addons, into other addons that don't have anything to do with the original exception error.

See a description here, coming from SODE's author who experienced the same issue: another module caused errors, and they were leaking into SODE, so it looked like SODE was the cause, but it wasn't:

http://www.fsdreamteam.com/forum/index.php/topic,13668.msg105608.html#msg105608

So, it's possible that, after a long flight, all these exceptions might eventually cause an OOM, which is usually what a crash in ntdll.dll means.

Could you try ANOTHER test ? Disable ALL other 3rd party modules *except* the FSDT ones in the DLL/EXE XML files ?

[kikigey89]

Could you try ANOTHER test ? Disable ALL other 3rd party modules *except* the FSDT ones in the DLL/EXE XML files ?

I did, still the same Only bglmanx.dll in dll.xml and couatl.exe in exe.xml.

What I forgot to say: FSUIPC automatically saves a scenario every 5 minutes. I'm currently always testing with the last scenario it saved this morning before the CTD. It is completely reproducible.
So usually I get a CTD with that scenario within 5 minutes.

[virtuali]

I did, still the same Only bglmanx.dll in dll.xml and couatl.exe in exe.xml.

P3D V3 has two set of XML files: some addons use the ones in %APPDATA%, other use the ones in %PROGRAMDATA%. Be sure you disable everything else (except our modules) from BOTH locations.

What I forgot to say: FSUIPC automatically saves a scenario every 5 minutes. I'm currently always testing with the last scenario it saved this morning before the CTD. It is completely reproducible. So usually I get a CTD with that scenario within 5 minutes.

You should disable everything for the test, which includes FSUIPC.

[kikigey89]

P3D V3 has two set of XML files: some addons use the ones in %APPDATA%, other use the ones in %PROGRAMDATA%. Be sure you disable everything else (except our modules) from BOTH locations.

You should disable everything for the test, which includes FSUIPC.

Good point, I forgot of the other set. Now FSUIPC is also disabled but still the same, still CTD.

[virtuali]

Good point, I forgot of the other set. Now FSUIPC is also disabled but still the same, still CTD.

Which airplane you used ?

[kikigey89]

My own one (for my home cockpit), I made the flight dynamics, exterior model is Blackbox A330. Default FSX A321 cockpit.

[virtuali]

My own one (for my home cockpit), I made the flight dynamics, exterior model is Blackbox A330. Default FSX A321 cockpit.

So you are now running your home cockpit without any modules ?

[kikigey89]

Exactly, I stripped it down to only the FS computer, without any external apps and just the dll and couatl.

[virtuali]

Exactly, I stripped it down to only the FS computer, without any external apps and just the dll and couatl.

Do you have an easy sequence to reproduce it with a default airplane ? I have just made a takeoff, a turn around the airport, then landed, taxied to Gate C6, called the GSX docking system, docked and turned off the engines, and I couldn't see any problems.

It took about 10 minutes, but you said it should appear in 5 minutes ? I'm using P3D 3.4 with the default B737 copied from FSX.

[kikigey89]

I attached my save file, I just climb to 37000 ft, heading 300 and speed 270. Should occur within 5 minutes, if nothing happens after 10-15 minutes then you do not have that issue.
I'm not sure, but I had the feeling yesterday that it appears when coming closer to the coast. The first time it happened south of Greenland and the second time 93 NM off the coast of Newfoundland.

[kikigey89]

Just a quick update as my tests continue: I deactivated my RAM disk and now it seems to be stable. Couatl is usually also on the RAM disk (the entire fsdreamteam folder) and maybe some part of the RAM is corrupted. As I installed KDFW my FSDT folder size increased which may forced Couatl to be written in a corrupted section.

[kikigey89]

Ok, I did a lot more tests. Memtest (6 passes) could not find any RAM problem.
Now I reactivated everything in exe.xml and dll.xml and the only thing which is different now, is that Couatl is NOT running on the RAM disk anymore. However all my FSDT sceneries are on the RAM disk. No problem anymore.

Do you have an idea what's wrong? I had Couatl on the RAM disk for 2 years now, without any issue. However after KDFW install it doesn't like the RAM disk anymore.

[virtuali]

Do you have an idea what's wrong? I had Couatl on the RAM disk for 2 years now, without any issue. However after KDFW install it doesn't like the RAM disk anymore

No idea but, it's clear from your tests the RAM disk configuration was a problem, and now you removed it, the problems went away

KDFW installation cannot have anything to do with this, since they just install the scenery and don't make any change to your system configuration, let alone something that might affect a RAM disk ( like a driver, for example ) so, fact you noticed it only after installing it, was only a coincidence.

In any case, using a RAM disk for Couatl doesn't make much sense, since the only thing that you might gain would be a slight decrease in loading time, but once it's in memory, it will be the same, since it's not a disk-intensive program. Its files are also very small, you can probably fit the whole GSX code in less space than a single 1024x1024 scenery texture...

Couatl it's a Python interpreter and, all the Python files that makes up for a program like GSX or the script that handles the scenery, for example, or the scripts that generates the scenery, are first loaded in memory, and then executed from there. A proof for this, is that you can even *remove* a program file, and the program will still continue to work, until you restart it. If the program execution at run time was in some way dependent on the filesystem it's stored on, you wouldn't be able to remove it so easily, and you would see an "access denied" error, like when you try to remove an active .BGL while the sim is running.

So, by running it from a RAM disk, you don't really gain anything, perhaps a *slightly* faster loading time (but it won't be probably noticeable compared to a fast M2 drive), but no actual performance gains.

[kikigey89]

The only reason why Couatl was on the RAM disk was that it was much easier just writing one line of batch script, copying just the entire FSDT folder instead of each single scenery :-)