Later: Replaced my FS9/Addon Scenery, FS9/Texture and FS9/Scenery folders with backed up versions from 2010 .. still get CTD.

Welcome to the CTD Club, see my Jackson WY post. I am now going to try the afcad route again. My mentor Mel, has helped me a lot, but anything is worth trying.If I find a cure I'll let you know.Echofox

Could probably be a dodgy bgl landclass file thats causing your problems. Dimi

Any idea where to search for dodgy landclass files, can't see anything on the install discs, or are you thinking add-on.With apologies Martin for jumping into your posting.RegardsEchofox

Back in FS2002, there was a limit to the number of items in the scenery.cfg file. I think it was 256 (two to the eighth) and I've wondered if this limit still exists in FS2004. Does anyone know? Does scenery have access to its "layer number" and does it make use of this? If you are installing older FS2002 scenery in FS2004, and it's at a layer above 256, that might be an issue. Try moving some of the sceneries you have installed above 250 down to lower levels.

Back in FS2002, there was a limit to the number of items in the scenery.cfg file. I think it was 256 (two to the eighth) and I've wondered if this limit still exists in FS2004. Does anyone know?

Some say there is a limit of 331 in FS2004, but its a myth. John

See today's posting "Jackson WY #2", may help you in a new direction. With help it's taken me a week to resolve problem.Echofox

Many thanks for the continued replies - I do appreciate people trying to help: FS is my no.1 love (apart from my family, probably!) and I go to bed almost depressed knowing my flights are CTDing (is that a verb?). To be honest, with so many solved CTDs under my belt in the past 10 years, I'd sort of come to look on them as a minor inconvenience - always easily solvable. And so they have been in the past, but this one has me beat - maybe it's teaching me not to be so blasé !! So .... no, not a dodgy landclass file (my usual prime suspect), as I still get a CTD with almost all my addons bgls removed. BTW, landclass files can lurk anywhere, often but by no means always starting with "LC_", but a programme called FlightSimManager will locate them all. Sadly the programme is no longer being developed and you need to turn your PC clock back to about 2002 to run it (or use RunAsDate - Google it - to do this on a programme-by-programme basis) but FlightSimManager is a really useful programme if you can be bothered to set up your PC so that it will run. There is a limit to the number of addons that will show in the scenery library - many of mine don't show any more, but I never go to the scenery library within FS9 now - indeed, the other day when I did want to go there I found I had forgotten how! However, you can add as many as you like to the scenery.cfg file by hand and (100% sure) they work there just fine. Again, there's a great little programme to make this a very easy task - Scenery Align (in the AVSIM library) - I wouldn't want to run FS9 without it now, I use it all the time. In any case, bgl files of any kind are not an issue per se, as I still get the CTD with the out-of-the-box scenery.cfg plus a few needed 3rd. party files - only 50 entries or fewer in total. If you read above you will see that it is not those few added entries that are causing the CTD, I won't explain again here.. Will look at "Jackson WY #2" .. and will report back. I may do a System Restore meanwhile too: as you say, anything is worth a try. Will also try a flight tomorrow, Vienna to Bucharest (i.e. LROP, where I get my '1st' CTD every time): I flew that same route 4 or 5 days ago and landed in Bucharest with no CTD. If there is one this time I will know something has gone very amiss in the last few days (but I didn't change or add anything in that time, so no idea what it could be!!). OK, thanks again. Will post back again tomorrow (bedtime here in BKK now!!).. M.

... just read "Jackson WY #2": wouldn't help I'm afraid as I already tried replacing my whole FS9/scenery folder with the default one (and the FS9/texture folder -as above) - still get a CTD.

Hi Martin, OK, do you use SCM2004 by the way, to add delete and analyse scenery files? Sounds like you know your stuff, but if you don't already use this, its very handy. My scenery.cfg has 383 entries with no problems. Some questions that may help here... You said that the your scenery cfg is OK with up to 250 entries and presumably no matter what you put in after that, you get CTDs. What do they look like? does the sim just disappear, or do you get a black screen, a frame freeze etc? You said "I also found that if I remove all entries after area.250 in my scenery.cfg file, plus one or two others below that number which seem to cause the CTD if I leave them in."Which sceneries do you have to remove below the 250 limit that also cause CTDs whatever their position?

• Presume you checked that the order of scenery files in your cfg is correct i.e. mesh and landclass below sceneries? (sorry if these are dumb questions).
• What is your PC spec and OS?
• Do you use add on weather eg Active Sky, Rex?
• Which planes are you flying when you get CTDs - have you changed planes to test?
• The appropriately named waypoint, 'obuga' is indeed south of Bucharest. I do not know if it is on any of the SIDS out of LROP as I couldn't find it. Have you tried departing via the VALPA 08L departure, that avoids obuga? Does it still happen using other SIDS? I haven;t looked on a Jeppesen plate so I could be wrong here.

btw I did the flight from LROP to LGAV in a Wilco Feellthere E175 at FL330. I have UT Europe and 383 entries in my cfg. I have freeware add ons for both LROP and LGAV. Departed LROP via obuga. Very nice route. Let me know. Regards, Ray

Thanks Ray. I haven't used SCM2004, but I think the Scenery Align programme I mentioned must be similar. I've downloaded it anyway and will have a look at it. To answer your points: - Yes, sceneries are in the right order. Mesh folders like FSGenesis should be at the beginning of the scenery.cfg (i.e the lowest number) to have the lowest priority. Only AES needs to be higher (otherwise I get issues). This is all explained on the FSGenesis site. - PC spec at the bottom odf each of my posts (signature) - Yes, use Active Sky. CTD with or without it. - Use a PMDG 747, but CTD with default Cessna too, and others I have tried - never realised however appropriately 'obuga' is named!! :-) As I said in my first post though, I am also getting the CTD when I head west instead - FS9 crashes at the VOR 'FLR', on a heading of 251 degrees from LROP. Haven't tried departing to the east yet ... The CTD inside Greece occurs a fraction before the waypoint 'exara' - N45.40.65 E24.00.18 M.

... just re-flew the LOWW to LROP flight I made a few days ago - again it was fine. I was directed to land at 08L and I can see that as the CTD occurs when I touch the VOR FLR or go to the south of it, I will always be OK landing at Bucharest, so long as I keep north of FLR (see screenshot). I've changed my LROP - LGAV flightplan too (2nd. screenshot) to ensure that ATC vectors me well away from the area south of FLR, whatever the runway I am given for T.O. - and also I approach Athens a long way to the east now compared to before, well away from the problem area there. Will fly this route a bit later and report back. It could be that this CTD problem has been there for ages and I have never noticed it before: I don't fly to/from Bucharest that often after all. Martin

Martin, Do you update your FSNav database every time you added new scenery items (particularly airports) to FS9?Do you apply Navigraph database updates for PMDG and FSNav?Do have any addon sceneries for LROP, Romania or Greece (eg HSP Greece) or is it all default in these areas? If you are getting crashes around specific waypoints it is probably not AFCADS but more likely a corrupt bgl as you originally said, or maybe even the FS9 internal database is affected. Have you ever had a virus for example on that machine? Anyway you say you have workarounds that avoid specific navaids/waypoints. The only fail safe way to eliminate the problem altogether may be a complete reinstall of FS9 unfortunately. I would hazard a guess that most of the FS/PC experts (I am not one), would advice you to do so in this case. In the past that is the advice I have received when I had certain problems. Of course you may solve it by just continuing to hack away at sceneries I did reinstall once a few years ago and it is good to refresh FS9 occasionally if you can stomach it and have the time. There is some good advice on the net about reinstalling FS9 (search for NickN's posts on this), if you haven't followed external advice before, this may be a good opportunity to do so and will only improve your FS9 installation. Hope you solve it whatever. Ray

I don't often get a CTD but this one is driving me nuts! Details here:I know ntdll.dll CTDs are the devil to troubleshoot, but what I have so far is this: CTD first happened just north of intersection 'obuga', a little to the south of LROP. So I changed my flightplan and headed west from Bucharest instead - but annoyingly also got the CTD roughly the same distance out (at N44.30.3 E25.44.1). Most times I can stop a CTD by removing certain 3rd. party software (often one bgl file - found by trial and error usually), but this time I have wasted hours with no result... However, if I replace my scenery.cfg with the default FS9 one, the CTD doesn't happen. I also found that if I remove all entries after area.250 in my scenery.cfg file, plus one or two others below that number which seem to cause the CTD if I leave them in, I also don't get the CTD. But adding any entries after 250, no matter what they are, brings back the CTD. Remove them and I can run the same flight (an AutoSave file loads about 30 seconds before the CTD) several times - never a CTD. The crash happens in the same spot every time and if I use the FS9 'map' to load the co-ordinates near where it occurs, rather than use the AutoSave.flt file, FS9 will still CTD. Have run chkdsk /f on my C drive and the drive with FS9. Still get a CTD. Deleted page file and rebuilt ... in vain. This surely must be software related, if the default scenery.cfg or a truncated version of my own file fixes the problem?

Possibly a corrupted scenery.dat file. You will find one in each individual scenery folder. Delete them all and let FS rebuild them. Doug

Hi spotted this"Errors caused by problems with ntdll.dll are commonly occurring in all of the "Microsoft Windows" operating systems. The universal solution to your problems is to download and re-install a new copy of the ntdll.dll file. Another more time consuming solution is to re-install your OS (Operating "cheers aNDY