1 hour ago, MrBitstFlyer said:

Thank you.  I just finished an update to all what you suggest.  EXPO was turned on in the BIOS (configures your RAM for those who like me didn't know!).  I turned that off but still the issue.  Something that was baffling me was running MSFS2024 without crashing issues, but I have noticed more stuttering in that sim.

Thinking this MUST be outside XP12, I created a bootable flash drive to run MemTest86 - and I think I have the culprit (I hope) - it detected a memory fault!  If I look at apps that display system specs, they all show I have 32Gb installed, which is correct, but MemTest86 detects a fault.

I wonder if XP12 is more unstable with a memory fault than MSFS (a vanilla XP12 is not affected by the memory fault?), because MSFS not crashing threw me.  Also I play a lot of Steam games and none of them crash.

Depending on where the bad block address is, it could be that vanilla XP12 is running in an address space that resides below the bad block, and putting in an add-on expands your physical RAM footprint up into the range where the bad memory block resides.

If Memtest86 reliably produces a fault at/near the same address, then you have a bad spot in the array, and it needs replaced.

If the error address(es) are widely disparate each time, it could be that you're running on the ragged edge of stability, and sometimes adding a little voltage to the memory in the BIOS can stabilize a misbehaving DIMM.  Motherboards aren't always precise in their set/reported voltages, either, so even if you have the design spec voltage set in the BIOS, it may actually be getting a bit less, and possibly enough less that the module isn't stable.

That said, the most common hardware failure I've enountered in over 35+ years of computer building is memory.  Odds are you'll need some new RAM...not a great development in the current insane market environment.

1 hour ago, MrBitstFlyer said:

Thank you.  I just finished an update to all what you suggest.  EXPO was turned on in the BIOS (configures your RAM for those who like me didn't know!).  I turned that off but still the issue.  Something that was baffling me was running MSFS2024 without crashing issues, but I have noticed more stuttering in that sim.

Thinking this MUST be outside XP12, I created a bootable flash drive to run MemTest86 - and I think I have the culprit (I hope) - it detected a memory fault!  If I look at apps that display system specs, they all show I have 32Gb installed, which is correct, but MemTest86 detects a fault.

I wonder if XP12 is more unstable with a memory fault than MSFS (a vanilla XP12 is not affected by the memory fault?), because MSFS not crashing threw me.  Also I play a lot of Steam games and none of them crash.

😕

Not a good time for a memmory error ... They cost a fortune now ...

10 hours ago, Litjan said:

I have a copy+paste procedure for cases just like this:

This is a guideline on how to cure your X-Plane problems of crashing or device loss errors (DLE):

1.) Make sure your operating system is in prime shape. No overclocking. Latest drivers. Default graphic settings (no esoteric Nvidia settings, etc.), no paranoid anti-virus, no "I got this on a cool reddit forum with Windows tips" stuff.

2.) Remove all third party content from your X-Plane installation. Physically move them somewhere else, disabling them in X-Plane is not enough. This includes plugins, aircraft, scenery. If you are not sure you can do this reliably, just delete everything and install X-Plane fresh.

3.) Fly a default aircraft for a very long time. Let it go on autopilot if you don`t have the time, but fly a default aircraft in a default ("vanilla") simulator setup until it crashes or you are sure that it is stable. The longer the better, I personally recommend to use it in this state for several long flights until you declare it stable.

4.) If the simulator crashed or you suffer a device loss error, file a bug with Laminar Research (google X-Plane bug reporter). Wait for LR to fix the problem. You can now post here and let us know about your problem, maybe someone can spot something wrong with your system that you missed.

5.) If you completed the long testing run with no problem, you can install your FIRST add-on. ONLY ONE! Repeat the long duration testing run. If XP crashes or has a DLE, you have found the offending third-party item. Do not use it anymore. Contact the developer of said item to fix it.

6.) Add your NEXT  add-on. Repeat testing, discarding all add-ons that cause crashes or DLE´s.

Remember, there are no "must have" add-ons. There are only compatible or incompatible add-ons. It is the developer´s responsibility to make his add-on compatible or take it up with LR if the problem is not on his side.

 

This is good advice. 
im thankful that the very few problems I’ve ever had with XP haven’t required anything as drastic or laborious, though!

generally in XP, and in most other system issues, I look first at whatever last changed. 
that’s usually some new addon or plugin or settings change, but can also be an UPDATE to formerly reliable software. Including, as you say, graphics drivers (occasionally) and windows updates (very rarely). 

8 hours ago, Litjan said:

The problem with AI is the same as the problem with guns and fast cars - humans often do not know how to use tools safely/correctly. Sitting there by themselves, neither guns nor cars kill anyone.

Current AIs (LLMs) are largely glorified google search machines. They can´t think, they can just look up stuff and condense what they found incredibly well.

This can definitely save you the time to read up on stuff yourself, but ultimately it´s knowledge is limited to the "knowledge out there". 

If someone (like the staff at Laminar) is good at reading a log.txt, but never posted anything specific about how to do that, AI will be clueless. 

EXACTLY right, good sir!

I treat AI as I would a conversation with an extremely bright child. 

or as we used to say in the Intel shack, “Trust, but Verify”.  😎👍

2 hours ago, MrBitstFlyer said:

I used a program called 'Driver Easy' that scans your system and shows all the files that need updating (with buttons to do the updating).  I hope that hasn't been a problem!

Graphics drivers are one of the areas with which to take care. 

the GPU folks are often rolling out new features just as much as stability fixes for old issues. Which can lead to new stability issues…

you might try rolling back a version or two. Check forums and see if other simmers are reporting issues. 

I also recommend you temporarily lower your graphics settings, even tho you have a strong system. 
you shared that things are generally okay except for flights running longer than 3.5 hours. 
to me, that sounds like a slow memory leak of some sort. 
and if you’re seeing positive tests of memory errors, that could point the finger even more strongly  

 

1 hour ago, UrgentSiesta said:

EXACTLY right, good sir!

I treat AI as I would a conversation with an extremely bright child. 

or as we used to say in the Intel shack, “Trust, but Verify”.  😎👍

Quite, but AI will suggest things that you may not think of when your knowledge is limited - as it did when suggesting creating a bootable MemTest86 drive 😊

1 hour ago, UrgentSiesta said:

Graphics drivers are one of the areas with which to take care

I always update the GPU driver separately because Driver Easy will always suggest the latest 

I rolled the GPU driver back and part of the testing.

2 hours ago, jcomm said:

😕

Not a good time for a memmory error ... They cost a fortune now ...

Yes, I don't believe it!  Now MemTest86 has confirmed faulty memory my flight SIM hobby is screwed - no way I can afford new memory at those prices on my pension 😥

59 minutes ago, MrBitstFlyer said:

Yes, I don't believe it!  Now MemTest86 has confirmed faulty memory my flight SIM hobby is screwed - no way I can afford new memory at those prices on my pension 😥

😔😔😔

I confess I was finding those successive crashes rather suspect 🥴

I hope you can sort it out. Some stores may still hold stocks of DIMMs at lower prices?

Edited December 11, 2025Dec 11 by jcomm

MemTest86 detecting errors.

 

Two and a half hours later test is complete and failed 😭

Edited December 11, 2025Dec 11 by MrBitstFlyer

5 hours ago, Bob Scott said:

Depending on where the bad block address is, it could be that vanilla XP12 is running in an address space that resides below the bad block, and putting in an add-on expands your physical RAM footprint up into the range where the bad memory block resides.

Sounds plausible thanks.  My PC  might go 30 minutes before crashing and sometimes every few minutes - my take offs outnumber landings by 100% 😭

Edited December 11, 2025Dec 11 by MrBitstFlyer

4 hours ago, Bob Scott said:

and sometimes adding a little voltage to the memory in the BIOS can stabilize a misbehaving DIMM.

Is this still worth doing considering the MemTest86 failed?

 

2 hours ago, MrBitstFlyer said:

Is this still worth doing considering the MemTest86 failed?

Memory failure test could be other factors, not entirely RAM.  Failing motherboard, failing IMC, power issues, etc. … it’s good to know that your RAM is failing memory test, but you still don’t really know why.

Best course of action is to remove any and all OC settings in the BIOS/EFI … especially remove the EXPO profiles, disable for now … then test again.

Edited December 11, 2025Dec 11 by SayAgain

31 minutes ago, SayAgain said:

Best course of action is to remove any and all OC settings in the BIOS/EFI … especially remove the EXPO profiles, disable for now … then test again.

Thanks - I removed the EXPO profile which changed the memory from 6000 to 4800, but several flights in XP12 ended with the same crashes.  However, I haven't retested with MemTest86 with the EXPO removed yet.

4 hours ago, MrBitstFlyer said:

Thanks - I removed the EXPO profile which changed the memory from 6000 to 4800, but several flights in XP12 ended with the same crashes.  However, I haven't retested with MemTest86 with the EXPO removed yet.

you could always just swap teh modules around you just never know