I'm having CTDs as well since latest hotfix. Just have PMDG livery installed. Didn't have any issues before.

I fixed the CTD with a registry repair, but still get an occassional freeze still with hotfix4 Joe

After following the advice to start FSX with a default a/c rather than the NGX I yesterday while testing got no CTDs with reference to the PMDG dll so for anyone else with the same problem try starting FSX with a default a/c or maybe even better yet remove the startup situation from your fsx.cfg by removing any text after the = sign.

OK, I have great news...still no CTDs after another rather long flight and I also found that it appears it's OK to use a saved situation as long as you change back to a default FSX a/c like the Cessna before you save the situation and exit FSX making sure it will be a default FSX a/c selected when you start FSX next time. This way you don't have to remember the exact location (gate) if you like me like to start at the very same location where you last left FSX making it as real as possible.

Don't forget about the X52, X52Pro issue. I still get the occassional Crash from time to time when loading up the NGX. For some reason that even Mystifys Ryan the NGX does not like certain USB controllers plugged in when loading the NGX. Solution is disconnect your controllers until your at the gate then plug them back in. Not saying this is just limited to X52s because there could be others as well. Only takes a couple seconds to find out if thats the problem. Or the other way is to load the PMDG 747-400 or MD11X first then switch to the NGX. Works every time. No idea why.

Update: I saw someone with the Go-Flight Moduels reporting a crash and after he pulled his hubs off the computer it stopped crashing so just for the heck of it try disconnecting your controllers.

Tonight I just noticed a new kind of CTD I didn't see before, I'm running FSX in fullscreen mode and all of a sudden I got a popup window saying "Microsoft Visual C++ Runtime Library" in the title bar and the message itself said... Runtime Error!Program: F:\Program Files...R6025 -pure virtual function call ...and after pressing the OK button to close the dialog I was sent back to the desktop with the normal message FSX experienced a failure and needed to close bla bla bla... Hope this was a one-time-only because after following the tip to always start FSX with a default FSX a/c I haven't had any more CTD before this one. I'm running the latest version...HF4.

Tonight I just noticed a new kind of CTD I didn't see before, I'm running FSX in fullscreen mode and all of a sudden I got a popup window saying "Microsoft Visual C++ Runtime Library" in the title bar and the message itself said... Runtime Error!Program: F:\Program Files...R6025 -pure virtual function call ...and after pressing the OK button to close the dialog I was sent back to the desktop with the normal message FSX experienced a failure and needed to close bla bla bla... Hope this was a one-time-only because after following the tip to always start FSX with a default FSX a/c I haven't had any more CTD before this one. I'm running the latest version...HF4.

I recently started getting this error as well. An d now it is occurring more and more frequently. Gideon Ward

I've seen this error (or one very similar) if I close the flight simulator window from the cockpit by hitting the Red "X" instead of selecting END FLIGHT from the FSX Menu. The way I've found to correct this error is to load into a different livery at a different airport. Ensure you close the flight by using END FLIGHT, and then I'm able to load into any livery at any airport, including the livery that was causing the error. Be well.

Me too had the faulting module PMDG_737NGX.DLL error and cTD with the latest hotfix. Could only fly the NGX when i loaded my flight with the default Cessna and then the 737. So i returned to the RTM installer (including 3 HF's) and now all is working as it did before. I can load my flight now with the 737 and FSX keeps running fine. Will wait for the SP to get the latest improvements/additions.

After posting this I did the exact same flight again and this time I had no problems what so ever so it seems to be a intermittent problem.Hopefully both this and every other kind of CTD problems will be solved once and for all after SP1!