System Specifications
- CPU: AMD Ryzen 7 7800X3D
- GPU: Nvidia RTX 5070 Ti (Drivers updated)
- RAM: 64 GB DDR5
- Hardware: WinCTRL (3M PDC, PAP3, PFP 3N), Thrustmaster TFRP, TCA Yoke & quadrant, custom Leo Bodnar interface with hall sensor and buttons
I am experiencing persistent, sporadic CTDs in MSFS 2024, specifically while flying the Asobo 737 MAX 8. The crashes are almost always Access Violations (0xc0000005 ) and seem to be triggered by interactions between the simulator’s memory manager (mimalloc.dll ) and external hardware bridges.
The error is extremely sporadic and almost random. Sometimes the sim will work, sometimes it won’t. The error can normally be triggered by launching a software that bridges my WinCTRL (previously Winwing) hardware to the sim. I normally run the Asobo 737 MAX 8. If I start that software (SimAppPro or Mobiflight) before the sim, the sim will crash when starting a flight in Free Flight mode. The crash consistently occurs when the hardware tries to sync to the sim. I have worked with the Windows Event Viewer, WinDbg, MSFS crash dumps, etc. The most common faulting module was FlightSimulator2024.exe, with WinDbg pointing specifically to the mimalloc.dll. The most recent crash dump shows a Null Pointer Write:
Exception Code: 0xc0000005 (Access Violation) Faulting Instruction: or qword ptr [rcx+38h], 10h Register State: rcx=0000000000000000 Attempt to write to address: 0000000000000038
Another log also pointed to an Invalid Pointer Read involving mimalloc.dll, which is more commonly seen in the dumps and crash reports.
I have found a workaround that works sometimes. I can start MSFS 2024, wait for it to load the flight, then start SimAppPro or Mobiflight and it will sometimes work.
If anyone could provide further insight as the cause of the issue, or even just comment that you have the issue, I would be very grateful. We are ultimately looking for a solution, but I have a feeling that it is a long way off.
Years back, in 2020, I used to get those errors quite often. I identified one possible cause when using Littlenavmap, with plane tracking enabled.
When I stopped doing that the number of CTD’s dropped significantly. On one particular 2-3 hour flight I enabled it at the very end, and within a few minutes my sim crashed.
Another instance that springs to mind was when using SPAD. On one occasion I was looking at a long list of simvars, and from the top I held down the down arrow key. This caused SPAD to scroll through the entire list at speed, and each step also reads in that current simvars value. Within 10 seconds the sim crashed.
So I’m reasonably certain that external software that interfaces with SimConnect, if poorly written, can cause such crashes.
Thanks for the information! I have also seen that most software is built for 2020, then has to use a bridge to read 2024 variables in newer aircraft, which can cause problems. It’s good to know that I am not alone in this issue and that it does happen across different programs.
What I would add though is that 2024 has hardly ever crashed for me. For 2020 I had a period of nearly three years without a single CTD. There were configurations that I just avoided, sim stability was greatly improved.
I didn’t have any issues with 2024 on PC until January, maybe SimAppPro got an update in the background. It’s curious how these issue pop up seemingly out of nowhere. The simulator runs perfectly fine without any hardware plugged in, and if I can get it to open it usually stays open now.
The best trick to restore stability is to first remove all addons, both software, and hardware. If the sim feels more stable, you can then start adding things back bit by bit.
If you had many Community addons, for example, you can 50/50 them, leaving one half in place for a few flights. Then swap to the other half. If you lose stability, the cause may be in that half. Then halve them again until you find the culprit.
In this case SimAppPro would be the first thing to fly without for a few flights, until you are reasonably sure it would have crashed batter a given number of flights. It may just need updating.
I’ve kept all my software updated and removed everything from the community folder during testing, as I had a lot in there. I was able to narrow down the issue to something with hardware, as the sim would run fine without it and then crash with extra devices plugged in. Initially plugging in one specific device would crash the sim, but then it became more random.
Crashes when USB devices are plugged in is an old 2020 issue, but that has been long since resolved as far as I know, but I guess it’s still possible.
What it could be is a device being disconnected rather than connected. Some devices will go to sleep if not used for a period of time.
There is a page on the SPAD site that describes this, and how to disable it per device.
Do any of your hardware components require an MSFS addon to work? If so, that could also be a cause.
The WinCTRL hardware uses SimAppPro to map the 7 segment displays and LCD screen on the MCP & FMC for the 737. It places a folder in the community folder, but that is the WASM module so that the sim lets it read internal variables. No other downloads are needed for my hardware. I have already disabled in Windows sleeping usb devices, that didn’t do anything. During initial testing, the sim could crash as soon as I plugged in the hardware.
A WASM module could well be something that interacts with the sim, and causes a crash. It might be worth contacting its developers to see if others have had this issue.
Hello ive been getting the same ctds, but the same issue and error message occured even after removing the winctrl wasm folder from the community folder and also the entire sim app pro app. i have a winctrl ursa minor
Hello @ItzChickenYall,
I unfortunately bring potentially bad news. I don’t have a solid answer for what causes this error. I had a butt-ton of time simply spent digging through crash dumps, Event Viewer reports, disabling things, reinstalling things, deleting things, and then one day it seemingly worked. Just to confirm, you are using MSFS 2024, correct? Not MSFS 2020. MSFS 2024 stores most user data files and configs in the cloud, which can make editing or finding them quite difficult. From what I can recall, I definitely had a WASM issue. The thing with WASM issues is that they seem to be very difficult to troubleshoot or resolve. My issue threw a error “0xc0000005” at offset “0x00000000032cd556e” in
Windows Event Viewer from what I can quickly dig up. This means that the simulator attempted to read or write a memory address in your RAM that is either empty, not allocated properly, or locked/in use by another process. We can’t exactly just tell it “don’t look there!” and try again. Let’s start with this: Try launching the simulator and having it crash (don’t make it crash, but if it does then we can use it to troubleshoot). Press “window key” and type “event viewer” while the sim is loading. I believe that you should see an Applications tab in Event Viewer. Open that and it should pull up a huge list of hiccups or errors windows occurs. When the sim crashes, look for an Error or Warning (there are often multiple warnings). That’s gonna give you some codes, take a screenshot and let’s compare. I’ll keep looking for some more info from when I encountered this error. It’s gonna take a while, but it’s not an unsolvable issue.