I just read with great interest the below post on this subject, but alas, it's just too complicated for me to understand and to try to use. I get the part about moving all (but maybe a few) aircraft out of FS into a stand by folder and I've read before about "unchecking" most of the scenerys in the scenery library that you are not using at the time, BUT how about just fixing the PROBLEM that caused all of this in the first place? I have been flying Flight Sims for twelve years and NEVER had this OOM error, untill...... I installed the Ultimate Terrain USA/Alaska and Canada "sceneries" a few weeks ago. Yea, I could always delete them and the OOM problem would probably go away, BUT, I love what this program does to my sceneries and I do not want to have to delete it. I just want to fix it. SURELY I am not the 1st and/or only one that has had this problem after installing this "scenery". Please, what did you other people do to fix the problem , or is there a way to fix the problem other than uninstalling it? Thanks jerrycwo4

I will sum it up quite easy for you Jerry. On your next format go with a 64bit OS and then patch the FS9.exe to be Large Address Aware.People can say what they want and this and that but since I moved over to a 64bit OS I have never had an OOM error and I have everything under the sun installed in my FS9 folder.

Jerry, before you go to the trouble of upgrading your O/S, have you installed all the patches for Ultimate Terrain? Some of them deal directly with out-of-memory problems. You can find them here:http://www.scenerysolutions.com/ut_downloads_FS9.htmlAl is right, of course, that a 64-bit O/S is the best solution for such problems, but I'd exhaust all other avenues first.

Also, make sure you do not have any empty "Texture" folders anywhere in your FS9 directory or in any folder referenced by the scenery.cfg file. It's a well-known fs9 bug that will cause a memory leak, and often in the adding/moving/deleting of scenery people forget to clean that up and get re-bit.CheersBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Jerry, before you go to the trouble of upgrading your O/S, have you installed all the patches for Ultimate Terrain? Some of them deal directly with out-of-memory problems. You can find them here:http://www.scenerysolutions.com/ut_downloads_FS9.htmlAl is right, of course, that a 64-bit O/S is the best solution for such problems, but I'd exhaust all other avenues first.

Obviously it is essential to install the bug-fixes, but my experience with Ultimate Terrain was that the bugs caused terrain.dll crashes rather than OOM errors so it is possible this may not resolve the latter issue. The best way to establish that is, of course, to experimentally disable Ultimate Terrain.

Also, make sure you do not have any empty "Texture" folders anywhere in your FS9 directory or in any folder referenced by the scenery.cfg file. It's a well-known fs9 bug that will cause a memory leak, and often in the adding/moving/deleting of scenery people forget to clean that up and get re-bit.

Sorry, but that is a "well-known FS9 myth" that seems to come round and round.Please see http://forums1.avsim.net/index.php?showtop...;hl=martinlest2 for more details.Kindest regards,John

There are only two working solutions. A 64-bit OS with FS9 patched to make it large address aware or use of the /3GB switch with the applicable USERVA setting (USERVA = 4GB minus 768MB for OS allocation minus your card's onboard memory) and FS9 patched to make it large address aware. Anything else will just be a stop gap measure.

Thanks to ALL of you for taking the time and making to effort to try to explain all of this. This just might be the most complex subject that I have ever tried to get a handle on ! I love Ultimate Terrain but what a price to pay for it. I'm sure a person with a Masters or Doctorite in Computer Science might even have trouble understanding all of this. There is lots and lots of info here and I'm going to try to use as much of it as I can. I really like my Fs2004 to run smooth, BUT, I can "fix" a CTD from a OOM lose within about 90 SECONDS ( I have to reset the views on my three monitors and use the "saved" flights from FS2004 and RD4) and be flying again. I might just have to settle for this "workaround". My OOM problem only happens when I make an hour plus flight. Thanks for the help. jerrycwo4

Sorry, but that is a "well-known FS9 myth" that seems to come round and round.Please see http://forums1.avsim.net/index.php?showtop...;hl=martinlest2 for more details.Kindest regards,John

John; Sorry, but the post you linked doesn't really say that at all. There's much more to the story than just to label the empty texture folder problem a "myth." The myth that Martin Lest referred to was the old wisdom that landclass folders should never have an associated texture folder. But that said, if a scenery or landclass bgl references a texture that can't be found in an empty associated texture folder, a nasty memory leak is the result, due to a confirmed bug in how FS9 allocates and deallocates memory during the attempted file open operation. There are two possible solutions to the memory leak: either to track down each and every offending scenery or landclass and solve its misplaced or missing texture file problem (preferable but very time-consuming), or to prophylactically remove all empty texture folders so that FS9 does not attempt to open them looking for something that it will not find. Use of a 64-bit OS or 4GBT (aka /3GB switch) only gives FS9 a bigger address space to operate in...in the presence of a memory leak, it will extend the amount of time before FS eats through all the available address space and an OOM occurs. OOMs can occur in a 32-bit environment without a memory leak...for example a PMDG B744 with 32-bit textures flying into ImagineSim's KEWR, with high-def clouds from a third party, and large amounts of AI traffic can trigger an OOM absent any bad scenery. It's this sort of limitation that a 64-bit OS or 4GBT best addresses. RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Sorry, but the post you linked doesn't really say that at all. There's much more to the story than just to label the empty texture folder problem a "myth."

Obviously that post says a lot of things about other matters but the relevant bit is:"It has been stated many times that landclass files should not be associated with a texture folder. As has also been said, this is not quite the case. The problem occurs when a bitmap or autogen file which the landclass bgl file needs cannot be found in the accompanying texture folder."That seems to be a rather milder situation than telling people to "make sure you do not have any empty "Texture" folders anywhere in your FS9 directory or in any folder referenced by the scenery.cfg file" which from all the evidence I can find will make no difference to their OOM issues whatsoever.John

Obviously that post says a lot of things about other matters but the relevant bit is:"It has been stated many times that landclass files should not be associated with a texture folder. As has also been said, this is not quite the case. The problem occurs when a bitmap or autogen file which the landclass bgl file needs cannot be found in the accompanying texture folder."That seems to be a rather milder situation than telling people to "make sure you do not have any empty "Texture" folders anywhere in your FS9 directory or in any folder referenced by the scenery.cfg file" which from all the evidence I can find will make no difference to their OOM issues whatsoever.John

John, once again, you miss the point. What evidence have you found other than misreading a paragraph in the one post you quoted? Making sure that there are no empty texture folders in the scenery paths prevents an FS9 memory leak which can occur if FS9 tries to find a texture file in an empty associated texture folder. What Martin is saying is that if a landclass file properly references a texture file in its associated texture folder, it's OK...that was once believed to be the cause of a memory leak. I agree with that point. But if a scenery or landclass references a texture that's located in another directory, and there exists an empty texture folder colocated with the scenery folder, then FS9 will first attempt to find the texture in the empty folder every time it needs it, and each time FS9 will allocate some memory as part of the the file open, find nothing in the texture directory, and then, due to a bug, fail to deallocate it, causing the memory leak in question. I have verified this experimentally, as have numerous others.Removal of all empty texture directories will stop this bug in its tracks, as will the more laborious work of ensuring that the texture files referenced by every scenery and landclass bgl exist and are in their proper places.So what I've recommended to people...that they ensure that there are no empty texture directories in their scenery paths, is still good and valid advice. It certainly can't hurt.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

No, I haven't missed any points and I haven't misread anything.No, of course it doesn't hurt to try it other than perhaps in terms of time wasted running down blind alleys. I have conducted my own tests and conclude this makes no difference at all. I don't really think there are many "well-known FS9 bugs", just ideas that get repeated over and over again in forums and, like the old game of Chinese whispers, the story gets bigger and bigger. But if its on the internet, it must be true, mustn't it? :o)But without doubt, it is part of good housekeeping to tidy up like that.Incidentally, a vanilla installation of Flight Simulator 2004 will have an empty texture directory referred to in the scenery.cfg . . . but it still works!Best wishes,JohnInformation Technology ConsultantDOS3 DOS 3.1 WIN2 WIN3 WIN4 WIN5 WIN6 and LOSE7Potterspury, UK

But if a scenery or landclass references a texture that's located in another directory, and there exists an empty texture folder colocated with the scenery folder, then FS9 will first attempt to find the texture in the empty folder every time it needs it, and each time FS9 will allocate some memory as part of the the file open, find nothing in the texture directory, and then, due to a bug, fail to deallocate it, causing the memory leak in question. I have verified this experimentally, as have numerous others.Removal of all empty texture directories will stop this bug in its tracks, as will the more laborious work of ensuring that the texture files referenced by every scenery and landclass bgl exist and are in their proper places.

Bob, that is an excellent summary. Technically, what happens is that the software creates a new "handle" (memory pointer) each time it attempts to locate a texture. That "handle," once created, is not released...If you monitor while FS9/X is running, you'll watch the "handle" count continuously increase to astronomical numbers, eventually exhausting the available pool of addresses.The same process occurs if a badly coded gauge (C or XML) generates a "race condition." Eventually the pool of possible "handles" is gobbled up, resulting in a program crash.

I have read this post with interest after recently fixing (I hope) my own OOM errors.I followed the advice that Bob (w6kd) advocates and found and deleted two empty texture folders.Placebo ?? maybe , but I can fly the routes that would guarentee me an OOM sim crash prior to deleting those two "offending" folders

No, I haven't missed any points and I haven't misread anything.No, of course it doesn't hurt to try it other than perhaps in terms of time wasted running down blind alleys. I have conducted my own tests and conclude this makes no difference at all. I don't really think there are many "well-known FS9 bugs", just ideas that get repeated over and over again in forums and, like the old game of Chinese whispers, the story gets bigger and bigger. But if its on the internet, it must be true, mustn't it? :()But without doubt, it is part of good housekeeping to tidy up like that.Incidentally, a vanilla installation of Flight Simulator 2004 will have an empty texture directory referred to in the scenery.cfg . . . but it still works!Best wishes,JohnInformation Technology ConsultantDOS3 DOS 3.1 WIN2 WIN3 WIN4 WIN5 WIN6 and LOSE7Potterspury, UK

John, he's trying to politely educate you. I, perhaps would not have the patience to reply as he has eloquently has. Please research better before steering people in the wrong direction. DOS3 DOS 3.1 WIN2 WIN3 WIN4 WIN5 WIN6 and LOSE7,Is not FS9. SchoooooMitch

John, he's trying to politely educate you. I, perhaps would not have the patience to reply as he has eloquently has. Please research better before steering people in the wrong direction. DOS3 DOS 3.1 WIN2 WIN3 WIN4 WIN5 WIN6 and LOSE7,Is not FS9. SchoooooMitch

Thanks Mitch, I think we are trying to politely educate each other - we have different views on this but my angle on this is that the "empty" directory is not the critical issue, but the landclass file with a texture directory that does not have its texture files in it (but maybe has texture files in there relating to other files) is the problem area. If that is the case (and it often is) deleting any empty directories will not achieve the desired result. The discussion I referred to explains that better than I can, I don't claim to be the source of this discovery.I try to keep smiling - my comment about DOS3 DOS 3.1 WIN2 WIN3 WIN4 WIN5 WIN6 and LOSE7 was just a joke by putting letters after my name. If that humour wasn't appreciated I apologise, I am aware that although we all speak "English" there are considerable differences in both the language and the humour on opposite sides of the Atlantic - for instance "Schooooo" and "Placebo" are words that I just do not understand. And you probably think I can't spell the word "humor". :o)I think Bob and I have agreed to differ on the subject. Let's leave it there.John