Mattie941

For those that are interested, SteveFx's suggestion in another thread has fixed my CTD issues: https://www.avsim.com/forums/topic/633405-appdll-crash-and-kb5025221/?do=findComment&comment=5039267

Thanks. This seems to have fixed my CTDs

Hi - I'm just trying to find a fix for this myself and thought I'd give your recommendation a go. What do you mean my the documents folder? Is this the folder where FSX save files are stored? Or do you mean the FSX root folder?

Thanks for the reply. I don't use SIMStarter so not a fix I can try unfortunately. I was just looking at Windows 11 upgrades, so glad you mentioned it doesn't work before I spent my money. For me, it always seems to be when I try to connect external programmes. It's not any programme in particular and can crash when I connect any of them. E.g., vasFMC, vPilot, FSrealWX, VA ACARS, etc.

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?

Same issue here. 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.

Thanks. 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.

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

Where did you find the latest version of SimConnect? How did you install it? I'm having issues with 10.0.61637.0 as detailed in my thread here: https://www.avsim.com/forums/topic/635654-fsx-apidll-crash-no-fixes-in-other-threads/?tab=comments#comment-4985819

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

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

I have been running FSX from a fresh reinstall. 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 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). I have recreated the CTD on start-up when the simulator crashes while at the splash screen before I can load the menus: 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: 0x5ec Faulting application start time: 0x01d9b313f32959f4 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: dc23c17b-fdb3-42dc-9e2d-66f93253de7d Faulting package full name: Faulting package-relative application ID: 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...

The crashes first started happening for me at the beginning of May. However, I was away for April so the timeline works regarding the Windows update. I have since managed to complete a few ~2 hour flights offline. The crashes are definitely more frequent on VATSIM. I run the latest version of vPilot as my client. I've had a error message from the FSX on startup "Flight Simulator has detected a problem with a third-party software program", blaming FSUIPC for thr crash. Could this be an issue with FSUIPC or vPilot and the April Windows update?

Hello, I keep running into an API.dll crash. I have completely reinstalled FSX. 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 Any ideas on what could be causing the crash?