FSX API.dll crash (no fixes in other threads)

[Mattie941]

Hello,

I keep running into an API.dll crash. I have completely reinstalled FSX. Therefore the FSX.cfg, DLL.xml and EXE.xml are all stock files. I have not been able to recreate the crash from the fresh reinstall at the moment.I have UAC turned off. I run on very minimal settings and I have monitored VAS and it is peaking at 2GB and yet I am still running into API.dll crashes according to the event viewer log. The sim also sometimes CTD with an API.dll error on start-up, before I get to the loading screens. The same issues persist with the sim installed on the SSD in C:\FSX and in it's current location on the HDD.

Example crash log:

• Faulting application name: fsx.exe, version: 10.0.61637.0, time stamp: 0x46fadb14
• Faulting module name: API.DLL, version: 10.0.61637.0, time stamp: 0x46fadb58
• Exception code: 0xc0000005
• Fault offset: 0x0003afa2
• Faulting process ID: 0x2fa4
• Faulting application start time: 0x01d9aeaeab4a9ebe
• Faulting application path: D:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\fsx.exe
• Faulting module path: D:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\API.DLL
• Report ID: 310022d2-51c7-41ac-acaa-e6bdbc0050e5
• Faulting package full name: 
• Faulting package-relative application ID: 

 

I have a 2017 Medion P6661 gaming laptop:

• GeForce GTX 950M Graphics card
• 15.6 Inch Screen
• Intel Core i5 6200U Processor
• 8 GB RAM
• 1TB Hard Drive + 128GB SSD
• Windows 10

 

I can only recreate the crash once I have installed FSUIPC and some addons to run using it: FSrealWX lite, FSFO v3, vasFMC 2.1, vPilot and Skytrack (my VA ACARS). The API.dll CTD does not seem to be related to any single one addon or combination of addons (I have tested with individual addons and combinations of addons).

 

From Process Monitor, the last file FSX tries to read before "Thread Exit" is the kernel32.dll file. The last file before "Process Exit" is the quartz.ttf file in the "Fonts" folder. However, in the Result column in Process Monitor, it reads "SUCCESS" for both. I'm not too sure what this means though...

 

 

John Dawson noticed that there is a mismatch between my FSX version and the Simconnect version:

•  31844 Running in "Microsoft Flight Simulator X", Version: 10.0.61637.0 (SimConnect: 10.0.61259.0)

I tried uninstalling SimConnect but the latest version on the FSX Acceleration SDK is 10.0.61259.0. When I reinstall and start the sim, I still have the same mismatch. Therefore:

• How do I remove 10.0.61637.0 so that the FSX version matches?
• Or where do I find/download 10.0.61637.0 to update my SimConnect version

[jorgen.s.andersen]

The cause of the crash is indicated here:

 

• Exception code: 0xc0000005

This tells us that "something" attempted to write to an area of RAM where "something" had no access rights. There is nothing, however, that says directly what this "something" is.

 

But in all the cases of this exception code that I have seen, with FSX or P3D, the "something" has turned out to be a badly programmed or incompatible add-on.

 

So I would propose this course of action: find a flight and a point in the flight where the CTD is guaranteed to occur. Then uninstall your add-ons one at a time and retry the flight until the CTD no longer occurs. Or, if you prefer, do a clean install of FSX only, redo the flight to make sure that it does not occur in a default install, and then install your add-ons, again one at a time - you get the drift.

 

If you elect to do the reinstall, then do yourself a favor and create a folder, for instance called D:\FSX, and install into that. Even if you turn UAC off, the \Program Files folders are still protected folders. 

 

The SimConnect question is beyond me, as I don't have FSX any more.

 

Let us know how it goes -

 

Jorgen

[Mattie941]

1 hour ago, jorgen.s.andersen said:

 

So I would propose this course of action: find a flight and a point in the flight where the CTD is guaranteed to occur. Then uninstall your add-ons one at a time and retry the flight until the CTD no longer occurs. Or, if you prefer, do a clean install of FSX only, redo the flight to make sure that it does not occur in a default install, and then install your add-ons, again one at a time - you get the drift.

 

If you elect to do the reinstall, then do yourself a favor and create a folder, for instance called D:\FSX, and install into that. Even if you turn UAC off, the \Program Files folders are still protected folders. 

 

Thanks. As I said in my first post. I am running a clean install of FSX, therefore no scenery or aircraft addons. The issue occurs when I try and connect an external program to the sim (vPilot, FSrealWX lite, etc.), which is why it has made me think it is a SimConnect issue. 

Regarding the install location. As I said in my first post, I have run the clean install in "C:\FSX" (SSD with my OS installed) and "D:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X" (additional HDD not running the OS, therefore it is not a protected folder). The install location of FSX does not make a difference to the CTD. 

 

 

I tried installing from Just Flight and from the Acceleration SDK. I run through the steps to install Acceleration SDK but when i run the SimConnect.msi, it still installs SimConnect 10.0.6129.0. It's strange because when I run the SimConnect.msi file, the "run as administrator" pop up asks if I would like to install SimConnect 10.0.61637.0 but then when I click "yes", the installer window appears it says SimConnect 10.0.6129.0. When I check for the version installed it is SimConnect 10.0.6129.0 and FSUIPC is still reporting a mismatch.

The file properties of the Microsoft.FlightSimulator.SimConnect.dll file in "...\Microsoft Flight Simulator X SDK\SDK\Core Utilities Kit\SimConnect SDK\lib\managed"says that it is version "10.0.616.37.0 (FSX-Xpack.20070926-1421)" and yet it does not install this version.

I'm not sure what I'm doing wrong?

1.  Found here: https://support.justflight.com/support/solutions/articles/17000100065-simconnect-files-for-fsx-p3d
2. 
3. 

[Mattie941]

A complete reinstall of Windows has not fixed the issue. Therefore I'm out of ideas...

[jorgen.s.andersen]

I need to ask you why you have this fascination with the versions of SimConnect?

 

If you, after a reinstall, leave SimConnect completely alone, do you get the crashes then?

 

Jorgen

[Mattie941]

I thought that the version mismatch was the issue, but it was not. 

 

It has recently been confirmed that the API.dll crashes (IF no corrupt dll.xml file) are being caused by a Windows update from a few months ago. It’s a shame.

 

I recommend everyone that is experiencing the issue to submit a support request with Microsoft: https://support.microsoft.com/en-us/home/contact

 

This will help increase exposure to the issue and will hopefully expedite a hotfix.

[Mattie941]

I recently tried running FSX again after the recent windows updates but I still get the API.dll CTD from a clean install of the game. Does anyone know of a fix?

[mrzippy]

API.dll – Indicates you are close to running out of memory (OOM). • Rename or delete FSX/FSX-SE or P3D.cfg, restart sim and let the configuration rebuild. Do not change any settings. This is a temporary fix just to investigate the cause. • Check BufferPools Tweak parameter in respective config and disable (fix for many). Disable by commenting out the line such as // in front of the parameter. • AffinityMask tweak has wrong parameters for your computer. Comment out the parameter to disable (i.e., // in front of the parameter in the config. • I

[Kalorien]

Hey mrzippy,

this has nothing to do with OOM. I run FSX VAS Monitor and I have plenty of memory left. On my computer it happens only sometimes. Really strange behaviour...

[jorgen.s.andersen]

What is in Windows Event Viewer at the time of the crash?

 

Jorgen

[Mattie941]

6 minutes ago, jorgen.s.andersen said:

What is in Windows Event Viewer at the time of the crash?

 

Jorgen

Mine can be seen at the top of the thread. From Process Monitor, I can see that the last file FSX tries to read before the CTD is the kernel32.dll 

[jorgen.s.andersen]

Sorry, I should have gone back there.

 

But you need to go back up there also and read my post about the exception code 

• Exception code: 0xc0000005

Because until you fix whatever is trying to write where it has no access rights, this problem is not going to go away. And it is not an OOM issue.

 

Jorgen

[Mattie941]

I have reinstalled Windows and then reinstalled FSX to a separate folder outside of Program Files (x86). The CTD still happens. 

 

My IT skills are not proficient enough to diagnose the exception code. 

[jgf]

A long shot, but make sure your account and system have full access to all folders involved.

[jorgen.s.andersen]

Matthew, I have already diagnosed the exception code, as described above.

 

I also, in my first post in this thread, out lined a course of action, which you need to follow:

 

"Find a flight and a point in the flight where the CTD is guaranteed to occur. Then uninstall your add-ons one at a time and retry the flight until the CTD no longer occurs. Or, if you prefer, do a clean install of FSX only, redo the flight to make sure that it does not occur in a default install, and then install your add-ons, again one at a time."

 

I repeat: until you find the offending add-on, this problem is going to continue to frustrate you.

 

You could maybe provide us with a list of your add-ons?

 

Jorgen

[Kalorien]

Hi,

 

I run FSX boxed Gold. Simconnect 10.0.61259 installed. Registered FSUIPC 4.977. Lvl_D 767 (did run like a charm in the past), PMDG 737NGX (also never a prob), CaptainSim 757 III (flawless) and FSDT GSX and GSX2 (which was a problem in the past, maybe someone will remember). GSX comes with Couatl and bglmanx. At the moment FSX is running with the 757 with GSX Groundservice, ok.

 

What I did now: All the networkfolders and the folders used by the sim (I think they are the same) reconfigured full access rights in windows. Recommended to: everyone. That is the easiest way, I think. My Windows 10 64 Pro only runs FSX, I do nothing else on the system. But the system is updated to 22H2. With StevesFixer it runs fast enough without OOM since I control it with VAS Monitor. I run 2 PCs with exactly the same setup. The difference is only: the second PC runs progs like ASN, FSC, LittleNavmap, Aivlasoft EFB2 Client, WideCLient, ProATC and others if desired. This PC is an upgrade out of Win 7 64 Pro. All programs have been tested right now for maybe half an hour, not more! Runs ok so far. PC 1 with FSX is still running FSX at the moment as I am writing here. The difference to the second PC is, it is not a Win 7 64 Pro upgrade.

 

What I did in the past (a couple of weeks ago): I decided to upgrade the SSD to a M2 module to have more speed on PC1 with FSX. I am still not sure if it makes a difference, but hey, now I cannot speed up anymore, because there is nothing to speed up more. The hardware is maxed out now. So I bought a 2TB M2 and made two partitions, one for windows, the other for FSX. I had to make a full installation of Windows 10 64 Pro (also updated to 22H2) and then install FSX Gold with all other things. That took a damn long time. Orbx, FTX Global, addon sceneries, navigraph and so on. A lot to do! I had to do it this way, because cloning did not work.

 

I know, I did the same access right configuration in windows in the past on PC 1 and PC 2. We will see what happens now. I will give another feedback later. Could take some weeks, because I am not sitting the whole day behind the monitor.

 

My system:

Haswell Devils Canyon running in turbo 4,4 GHz, it is a K version but I never overclock

MSI Z97 Gaming 5

M2 Kingston 2 TB and two othe SSDs

GSkill 2x 4GB 2400 TridentX DDR3

Asus GTX 1080 ti 11GB (less might also work )

 

FSX in DX10 runs fine. I do not complain. And!!! No, I will not buy a new Simulator!!!! Sorry

maybe the Steam Edition for 6 bucks...

 

[Mattie941]

4 hours ago, jorgen.s.andersen said:

Matthew, I have already diagnosed the exception code, as described above.

 

Thanks Jorgen. As you can see from my previous message, I have reinstalled Windows and FSX. The CTD occurs on the default install 

 

8 minutes ago, Kalorien said:

What I did now: All the networkfolders and the folders used by the sim (I think they are the same) reconfigured full access rights in windows.

 

 

Thanks for the feedback. How do I do this?

[jorgen.s.andersen]

If the error occurs on a default install of FSX, guaranteed without any add-ons, then to which folder did you install FSX? The default location under C:\Program Files(x86) is, hmmm a less than ideal location. Create a folder called for example C:\FSX and install to that. Even better if you can do it to a different drive than C:.

 

You also need to give yourself Administrator rights. Google on how to do this.

 

And finally, when you get to installing: turn anti-virus off completely, and run the FSX installer as Administrator.

 

Jorgen

[Kalorien]

2 hours ago, Mattie941 said:

 

Thanks for the feedback. How do I do this?

 

You must be careful! You do it by yourself and I won´t give any further assistance!

Check here ---> https://www.thewindowsclub.com/change-files-and-folders-permissions-in-windows-10

Google and you might get there.

[Kalorien]

Okay, FSX is still crashing. I hope not to make a whole reinstall. Pfff. Damn.

[jorgen.s.andersen]

A good thing to do is to turn off User Account Control, which will stop Windows from interfering when you try to do something with your files. Here's how:

 

https://articulate.com/support/article/how-to-turn-user-account-control-on-or-off-in-windows-10

 

This works in Windows 10 and 11.

 

Another thing is that your Windows, as well as some other libraries, need to be up to date. Run Windows Update, and in Update, under Advanced options, make sure the switch "Receive updates for other Microsoft products" is set to On. Leave this switch in the On position.

 

Jorgen

[Kalorien]

Thank you Jorgen,

I missed the the "Receive updates for other Microsoft products".

[jgf]

1 hour ago, jorgen.s.andersen said:

A good thing to do is to turn off User Account Control

 

Lol, after my first week with Vista I killed UAC and never allowed it since (astounding that MS lets us turn it off).  Has become so routine I don't even think about it.

[Mattie941]

3 hours ago, jorgen.s.andersen said:

Create a folder called for example C:\FSX and install to that. Even better if you can do it to a different drive than C:.

 

On 7/11/2023 at 9:05 AM, Mattie941 said:

As I said in my first post, I have run the clean install in "C:\FSX" (SSD with my OS installed) and "D:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X" (additional HDD not running the OS, therefore it is not a protected folder). 

 

I have tried installing FSX in C:\FSX and to the D:\ drive but both still cause the CTD

[Kalorien]

Hi Matthew,

your simconnect 10.0.61259.0 is correct. I assume a corrupted file somewhere in FSX. If your sim crashes right after the installation, from my point of view there are only three options. Your FSX CDs are old or the installation process is not correct. Your c drive SSD (256 GB?) might be not enough for FSX. It could also be possible that your SSD or your HDD (1TB?) are defektive. There are tools to check that.

I am still testing my system. The crash happens at LGAV but it does not happen at EDDF with the same aircraft. So maybe there is something wrong within the scenery. I'll keep on testing.