.....what was your default flight at the time....if FS9 was trying to start with the plane you deleted maybe this was why you got the Initialize failure ..........maybe download the plane again and put it back in the aircraft folder?...or have you tried that?
...As for the Dem4km.bgl file, which I believe has to do with the default scenery, it lives in FS9\Scenery\Base\Scenery, (8MB in size.)
Just get your original FS9 disks out and reinstall the file. It's on Disk 3 in msgame8.cab ..just copy and paste it to replace the damaged one......hope this helps.............commoner

...Must be longer than you think Ozzy..it's disc #3
