A few weeks ago I was faced with a PC which continually crashed when running an absolutely virginal installation. By virginal, I mean complete fresh download of X-Plane, with no plugins or addon’s of any kind installed.
Every test I performed on Windows showed no fault. Not even stress tests. Other programs worked without problems, but not X-Plane 11. The hardware was not brand new – but still pretty much state-of-the-art , but this was the first time it was used on a dedicated X-Plane machine.
X-Plane stubbornly crashed ( or better said, it froze) after a few minutes.
I was tearing my hair out!
Then, just by chance, I touched one of the RAM modules. It was HOT. The module was fitted with a nice heatsink—it wasn’t just a board with exposed chips. But still… it was hot—too hot.
I got one of those clip-on RAM module coolers (They are cheap at Amazon) :

and I added another chassis fan which was pointed straight towards the RAM modules.
Result? No more X-Plane crashing.
Moral of the story:
The CPU, GPU, and motherboard might be adequately cooled, but don’t forget to check the temperature of the RAM modules, particularly if you are using one of the XMP modes.