Having not previously suffered from the problem at all, I am now getting persistent CTDs, even with Joachim's fix installed and the other terrain.cfg fix applied. FS9 won't actually load at all now- it gets to 99% and then CTD without warning or error message.Anyone know what might be causing this and how I might sort it?Thanks in advanceM

Are you sure your only using one terrain fix or the other, not both at the same time?Lee

HiI actually have both installed at the same time- ie Joachim's terrain.cfg file with all maskclassmap=1 and maskclassmap=3 set to =0.

As an update, I have now gone back to the stock scenery.cfg file (eg no addon scenery (mesh etc) at all), and I still get CTDs. It seems the offending dll's from the error reports are "sim1.dll" and "ntdll.dll".Not sure where to go now, apart from a full reinstall...

Try using only Joachim's terrain.cfg file. Move your others out of the directory. Be sure you put his textures in your main texture directory. Also check that you do not have any duplicate AFCADs for the same airport. Also, experiment with removing addon mesh sceneries. Occasionally they can cause problems. I also notice that some installers for scenereies can occasionally re-write the scenery.cfg in funny ways. Re-numbering incorrectly and the like. Examine the scenery.cfg from time to time and make sure it looks right. This can cause problems.Lee