I purchased the PMDG 777, and started having OOM errors. I did some research on their forums, and they said this aircraft uses a lot of VAS (Virtual Address space), along with add on sceneries, weather programs, etc.. They suggested a program called scenery configuration editor, which allows you to disable all of your add on sceneries, except the actual airport you are flying out of and into. They said this will free up VAS memory, which has a 4GB limit in FSX, thereby eliminating the OOM errors. I tried this, and it works. One problem I am having, though, is that when I disabled (not uninstalled) the FSDT sceneries, when I enable them again with the scenery config editor, the buildings are not showing up at those airports in FSX. I then have to rerun the stand alone addon manager, and that gets them to show up again. however, not all the time. For instance, I enabled Hawaian airports 2, so I could take off from PHKO. No buildings! I reran the addon manager, and now they are there, but there also appears to be default buildings showing up and coming through the FSDT buildings. Very strange. I made sure when I ran the addon manager, all of my firewalls and virus scanners were off. I also set them up not to scan the coutl.exe and bglmanxx files (not sure those are spelled right here, lol). My FSX.exe file also does not have any of the compatiblity modes checked under properties. These are the only sceneries I am having these problems with, are the FSDT ones. I am sure it has something to do with the coutl.exe file or the other one. Can you shed some light on what it happening, and how to fix this permanently? I don't want to have to run the addon manager every time I enable or disable one of your sceneries. Thanks.