Yes, I have been getting the exact same error as well. Tried manual as well as the installer on Windows 7 Ultimate 64 bit with a Freshly installed version of UFO Defense from Steam. I originally had it installed in a SteamLibrary on a separate drive from C drive, then transferred the game over to my regular Steam library on C when it didn't work. Finally, tried a manual install to no avail. Still getting that message... Any help would be appreciated... maybe I just need help having the obvious pointed out in front of me...