I posted this to Flight1's UT forum but I think this is also a general FS story:Despite my previous optimistic posts here after making adjustments to my Fs, I still suffered from continuous CTD

Would suggest that you look for some duplicate AFCAD files as FS9 does not like these and will produce a CTD as you describe and also as a "Terrain.dll".An easy way to do the scan is to use a utility called ScanAFCAD availble in the file library here at AVSIM.File name is: scanafd.zipHope that helpsEd GreenKCLThttp://www.panelshop.com/DEV.jpg

To clarify, you must have the default AFCAD file and then are allowed only one more as an add-on. UT2 installs AFCADS (file name starts with FL----) for many locations. So at this point you have reached the limit for many locations.If you install scenery that adds AFCADS or have downloaded more complete AFCADS, then you need to move to a holding folder out of reach of FS the FL---- AFCADS installed by UT.You can examine AFCADS in question by opening an airport in AFCAD221.exe and it will list all for that airport. When you select the layer the file name will appear in the title bar. When you have more than the base and one other layer, look at the extra layers noting the file name and choose which one you wish to keep. You do not need FS running to do this. After you move undesired files out of the way when FS starts it will rebuild the scenery database. The next time you start AFCAD it will only show the current layers.If you are using FSUIPC to enable the UT TCAS gauge or Palm Spotter, be sure you are using FSUIPC verion 3.48 or later.Another check is to run your flight in clear weather in case you are using add-on cloud textures that may have a problem. If you added any scenery textures or elements that could also be a problem. Try a different flight in a non-modified region using a default aircraft to check things out and work-up from there.