Is that the exact error? Before panicking, have you tried the (hopefully) obvious:
Are you trying to open the file from the "Recent Files" list in the File menu and did the file get moved (or renamed)?
What order are you opening? Open Gmax then "
File > Open" or double clicking the
.gmax file in Explorer? Try both.
Please say you at least have "Auto Backup" enabled (it's on by default). If so, look in the folder:
C:\Gmax\Autoback\...
You should see (by default) 3 files named:
Autobak1.gx, Autobak2.gx, Autobak3.gx
Try opening the most recent from the "
File > Open" menu (you will have to select
*.* all file types) to see these.
Hopefully one of these is in good working order and should be as recent as the last time you exited Gmax (without crashing).
Assuming this works, (and even if it doesn't) you will then go to the "
Customize" menu >
Preferences >
Files tab, and check the box that says "
Increment On Save" and get in the habit of hitting
CTRL + S often.
Seriously though, I do hope you don't have to start over.
-Michael.
(but I wasn't kidding on that last point.. you will find it to be a God-send).