I have PMDG 747, the 747-8 expansion and PMDG 737NGX. Everytime I fly for more than an hour the game does a CTD. Last night I flew from KHOU to KDSM and as soon as I was about to land the game did a CTD. I have tried the "HIGHMEMFIX=1" and still nothing. Any ideas? I have also tried the uiautomationcore.dll fix and still the crash. It only happens with my PMDG aircraft. They are great products, I just wish I could fly them without the CTD.

Try running FSX with a much lower visual quality than you would normally accept, just to see if the symptom changes.

and what scenery packages have u got installed if you have orbox than it mite be one of the reasons and what are your pc system, bit hard to solve your problem if you dont give any details