I read many posts before starting my thread - to no avail: I am rather resigned to living with this (sigh!) as I don't see how I am going to troubleshoot it.With other CTDs I was used to finally tracking down a culprit - often a landclass bgl - removing it would cure the problem. But with these ntdll errors (which crash FS9, but not the PC I should add) when I restart my crashed flight more or less at the point it crashed (thanks to AutoSave), it may crash again one or even two times, but so far the flight will continue as normal after I re-run it, or at least after a couple of tries. So I assume it's not a specific bgl that is causing it and that deactivating sceneries isn't going to help (why would a scenery cause a CTD one time and not the next?)The CTD can occur an hour into a flight, or often it doesn't happen at all (and it can happen with any a/c as far as I can tell) so removing one of my installed sceneries and then NOT getting a CTD isn't going to prove anything.My CPU (i7950) was overclocked by the manufacturer, and in any case I have run FS9 overclocked like this since last summer without any problems - the ntdll errors have only reared their ugly head in the last couple of weeks. Besides I have read in several posts from others that cancelling their overclocking didn't help with the ntdll.dll CTDs...As I say, I am not expecting a miracle cure to this, but of course it does become rather depressing suddenly to hear 'silence', look up and see the black screen - 'oh $%£"%!!, not again!!". But perhaps someone has some insight that I haven't read about yet in my browsing..MartinScreenshot, for what it's worth

I read many posts before starting my thread - to no avail: I am rather resigned to living with this (sigh!) as I don't see how I am going to troubleshoot it.

You say you have read lots of threads - what have you tried?John

Hallo Johnhinson.Have a look at this site : http://process.networktechs.com/ntdll.dll.phpWilly

Hallo Johnhinson.Have a look at this site : http://process.networktechs.com/ntdll.dll.phpWilly

Why? I don't have any ntdll.dll problems myself. I do have a range of suggestions for martinlest2 but I am certainly not going to spend a lot of time writing out things that he will probably say he has already tried.John

Just seen the replies - have to go out right now, so will post back ASAP. Thanks!Martin

Well, not much, John, is the answer. Although I have been flying FS for 10 years - and create sceneries/files/repaints etc. and therefore consider myself more or less at 'expert' level - frustratingly, I don't really know where to start with this one! I turned off the overclocking but that didn't help (so turned it back on. I get such a performance boost from the overclocking, that I would probably rather put up with the CTDs than permanently delete the o/c - but it doesn't seem to be an o/c problem thankfully). I know the machine is running fairly cool, so that's not it either. No viruses found etc., but that was a long shot.So, I am not sure how to proceed - all my usual troubleshooting methods of removing sceneries till I find the culprit etc. won't work here because, as I say, having made no changes to my FS9 setup, I often can't reproduce the CTD when I immediately go back and fly the same flight (from the same point, using AutoSave).The only other thing I can add is that the CTDs seem to have happened in a large area that would be called 'The Balkans' - more or less. Croatia, Serbia, western Greece and so on. But I am not sure that that is relevant at this stage - that's just where I have had the CTDs since I started noting exactly where they were occurring.Advice therefore very welcome. Thanks.Martin

Well, not much, John, is the answer. Although I have been flying FS for 10 years - and create sceneries/files/repaints etc. and therefore consider myself more or less at 'expert' level - frustratingly, I don't really know where to start with this one! I turned off the overclocking but that didn't help (so turned it back on. I get such a performance boost from the overclocking, that I would probably rather put up with the CTDs than permanently delete the o/c - but it doesn't seem to be an o/c problem thankfully). I know the machine is running fairly cool, so that's not it either. No viruses found etc., but that was a long shot.So, I am not sure how to proceed - all my usual troubleshooting methods of removing sceneries till I find the culprit etc. won't work here because, as I say, having made no changes to my FS9 setup, I often can't reproduce the CTD when I immediately go back and fly the same flight (from the same point, using AutoSave).The only other thing I can add is that the CTDs seem to have happened in a large area that would be called 'The Balkans' - more or less. Croatia, Serbia, western Greece and so on. But I am not sure that that is relevant at this stage - that's just where I have had the CTDs since I started noting exactly where they were occurring.Advice therefore very welcome. Thanks.Martin

Well it fascinates me that you have read up on the subject but all you have done is fiddle with overclocking as I am not aware that relates to ntdll.dll errors. That being said, over-clocking is an adventurous business and I have always avoided it.Presumably you are aware that ntdll.dll is not part of Flight Simulator but a core part of Windows. There is a lot on the web about dealing with such errors and the general view would appear to be that it is affected by drivers, in particular situation where a driver has been updated and other associated ones have not. This is where I would look first, by either updating all drivers or if all are found up to date then rolling back any driver recently upgraded.I would just urge a little caution if you go Googling - a high proportion of "help with driver problem" sites are just giving you an automated answer that is not specific to ntdll.dll (although they may appear to be) and their sole purpsoe is to get you to download their super-duper fix-all software or registry repairer. They will gleefully tell you that your setup is teetering on the brink (when it probably isn't) and personally I wouldn't touch such stuff with a barge-pole - these could well be dodgy files and far from fixing your computer you could be making things significantly worse!Notwithstanding what I have said above it is obvious that for you the dll problem is only occurring with Flight Simulator. Whilst that does not mean it is FS's problem, there are obviously things you can do to eliminate whatever is clashing, for I am pretty sure a nice clean vanilla version of FS would give you no such issues.You need to consider the factors around you - does it happen with a specific aircraft, a specific location or intermittently at a specific location (try changing the clock to a different time of day, different season etc). This can tell you a lot.First of all, check that either

• Render to Texture, or
• Reflections

are turned on in FS's settings. With some add-on aircraft you must have one or other of these options turned on. This is critical.AI aircraft with reflections can cause this fault when first loaded at a distance from the user aircraft. Try running your FS with AI turned off as an experiment. You may have a dodgy AI aircraft, if so this will take much patience to eliminate.I have occasionally had this error and seem to have resolved it by fixing dodgy A&F ("AFCAD") files. Don't ask me why they should set ntldll.dll wobbly but the two instances I have experienced were:

• where there were multiple A&Fs for the same airport with differing co-ordinates
• where the airport was designed badly - there were AI parking spaces but the runway was marked as closed.

I do not know why these should give such a problem but it is worth checking anyway. As so many factors are involved it is difficult to be certain that really was the issue.Hoping this helps,John

Martin, You know that FS9.exe caused the failure in NTdll.dll,, But what caused the error in FS9.exe? Use the event viewer in Win7. ( Start / Run - type in "eventvwr" ) From that, expand the "Windows Logs" tree then select "Application". ( Left Pane ) In the Center, Upper Pane find the application error by using the approximate time when it happened, select the one(s) closest to the time by clicking on that event. Then... Look in the Lower Center Pane that will show "Faulting Application Path" = Path/FS9.exe -- You found the one(s) that caused it. In that same pane find "Faulting Module Path" -- That will give you the .dll in FS9 that faulted narrowing down where you should look.. IE acontain.dll = aircraft container, aircraft.cfg, air files etc..AI_PLAYR.dll = AI aircraft, schedulingControls.dll = Human InterfaceG2D / G3D.dll = Graphicsgps.dll = GPSPANELS.dll = Panel.cfg, panel bitmaps, Gaugesetc.. etc.. There was a fine site that listed all the dlls in FS and where to look for that particular error, but I'll be darned if I can find it.Hope this may help.RomanP.S. How clean are the fins under the fan on your CPU cooler?P.S.S - We ( U.S.) are right about the time for a Daylight Savings Switchover, many scenery problems do crop up then go away right around now.

There was a fine site that listed all the dlls in FS and where to look for that particular error, but I'll be darned if I can find it.

Possibly the one in my signature?(If you have signatures turned off in your forum settings, it is http://www.adventure-unlimited.org/)John

John, That was it! Thanks! Now bookmarked :-)Roman

Hi,Thanks for the replies. Yes, I know ntdll.dll is a windows dll file... And yes, a number of threads I read during the week cited overclocking as a possible cause - but who knows? My PC came overclocked - it has cooling adapted to the o/c - and although I did have some troubles at first (booting mostly - not in FS9 that I noticed) once I turned the o/c down a shade, everything has been fine. FS9 ran for several months (i.e. since I bought the PC) at the same o/c with no problems before the first ntdll CTD a week or two back.I think I can safely say that I do not have multiple AFCADs (I have run a batch script to collect all my AFCADs into one folder - and not just the type AF2_****.bgl - then checked for duplicate ICAO codes and instances where the script wanted to overwrite an existing file (suspected duplicate): after cleaning out 3 or 4 duplicates I did find, I ran ScanAFD - all OK). I have not changed any drivers since the problem began. I have read quite a bit over the last week, but as ever online do not automatically trust what is said there (e.g. re. drivers) - and as you wisely advise John I do not pay too much attention to these panacea downloads that are so prevalent. I've been working with Windows and tweaking it since Windows 3.1 so am fairly OK with what to do and what not to do (though far from infallible of course!).I had already checked for Render to Texture and Reflections settings (sorry, forgot to say so!) - they are set as they should be.As I say, I have had this CTD with a number of aircraft (three I think, all quite different) so doubt it is a/c specific. My AI a/c installation has not changed for over a year, so unless something has become corrupted, I doubt also if that is the cause. I will try turning my AI off - though as I said, the main problem is that it would take dozens and dozens of flights with no CTD to make me suspect that might be the cause. I only get the ntdll.dll CTDs every now and again. It is SUCH a pain (obviously) troubleshooting a problem that is intermittent!I haven't yet checked in AFCAD2 whether any of the airports I have recently installed (only a handful) has an error of the type you mention re. parking. I have fixed a number of these in the past (though they didn't cause any problems) so can easily look into that. Assume no problems found if I don't report back..I was perhaps stupid not to look at Event Viewer right after the CTD. But I thought that in Win7, the error information ,as per my screenshot, just duplicated what was in the Event Viewer. Is that not so? Whatever, I use EV quite often - have a direct shortcut to it on my desktop, but now that I don't recall the exact time these CTD occurred, I am not sure which errors are relevant. But the various FS9.exe errors since 27/03 refer to a number of dll files: ntdll.dll (of course), weather.dll & terrain.dll. Oddly, no red errors show for 28/03 - the day I had the CTD which lead me to post here.The cooler fins look OK - I dusted the PC recently. The temp probe on the CPU shows the temps as OK. As for daylight saving time - yes the CTD occurred on the day we were changing over in the UK (clocks forward), but the first ntdll CTD I had was a week or so earlier..Thank you all for taking the trouble to reply. I hope my answers are of some use...Martin :Batting Eyelashes:BTW - I had read that fault finding page (on your signature John) a year or two ago and saved it to my hard disc. I did read that before posting this, but there weren't really any ideas that helped...

I had CTDS from Fs9 as you described, no certain exact same time or place and eventually fixed the errors on my machine by reviewing the event viewer. There IS a record of what happened. After I corrected the issues, no more CTD. I had about 2-3 things going on. Its a basic troubleshooting technique. The earlier poster had it right. Use event viewer and fix the issue. If you are getting yellow OR red issues, fix them. What else can we tell you? You have to qualify the computer. But if you want to knock your head around trying to find a scenery file or afcad, have at it.Since I corrected each issue, I've been able to fly for over 24hrs and more. Done several around the world trips since. Just no issues. Event viewer is clean.Good luck.

Last time I saw this same sort of intermittent dll error (it was also ntdll.dll), it was an advance indication that I had a memory module getting ready to give up the ghost. The C0000005 exception code means that ntdll experienced a memory access violation. In my case I had intermittent failures over the course of a month...I'd run MemTest and OCCT for a few hours each, come up clean, then FS would crap out again--sometimes quickly, sometimes after a few days. Eventually the failing DIMM started throwing thousands of errors during a run of MemTest 86+, and reinstalling a fresh triplet of DIMMs ultimately fixed the problem.I'd start by running MemTest 86+ overnight, and then running a composite CPU/RAM stress test like OCCT, also overnight.If that produces nothing, try dropping your RAM clock speeds and/or possibly loosening the RAM timings and see if the problem reoccurs. Sometimes gradual degradation of components can cause a stable overclock to cease to be so...this is a fairly common problem with RAM modules running at aggressive voltages/timings/clock speeds, which would include pretty much all 2000 MHz memory modules. If that doesn't do it, try removing one of the three DIMMs and run with 4GB in dual-channel mode, and if you get the error again, swap the modules around until you've duplicated the problem with each of the three DIMMs out of the machine at some point. Also, if you have a monitoring utility that works with your mobo, watch the Vdimm voltage--many motherboards will overvolt the RAM beyond what's set in the BIOS setting, which can hasten the demise of an iffy module, especially one running near the physical limits of even the best-binned chips.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

So far, I've run MemTest v4,20 for several passes - no errors have shown. The memory is 3 x 2048MBs PC3-10600 XMP RAM, but as recommended on various specialist forums (I originally had a few problems with the PC as delivered and used sites like overclockers to modify settings) I do not have the memory set as xmp and it is at a lower clock speed than 'normal' for this RAM (800MHz I think). It's worked fine like this for some months.I haven't got round to doing the other hardware tests you mention, but am becoming more convinced (though far from totally so) that it is an addon doing this - as far as I recall I only get CTDs in the areas around Croatia/Bosnia etc. I flew Heathrow to Vienna last night for instance with no problems at all. I may disable some of the sceneries in 'suspect' areas, but as I am moving abroad for my job this month, not sure how much troubleshooting I am going to get done otherwise. (The FS PC will be shipped out at some stage, so I can continue once it arrives - tropical climate, so that's another possible worry - have to make sure the PC is in an air-conditioned room!).Thanks again folks for the input.Martin