I have both games linked through Steam (Easier for me to find all of my games on my PC) and I keep getting an error called 'Cannot open file fsgame.ltx'. I can run 'em just fine outside of Steam. I just want to know if there's a fix for this? Also I have Shadow of Chernobyl linked through Steam and it works just fine.

Basically the problem is the game is confused about were it is, as strange as that might sound.

You need to change the "Start In" or working directory. If you check the properties you should see that field with a value of a directory.

Now I can't remember off hand what it should be and I don't have the games installed to test and don't really use Steam so this is going to be an educated guess, try making that "Start In" path the same as the games install location (the games root). For Example "D:\Games\Stalker\" , while the "Target" path is something like "D:\Games\Stalker\bin\xrEngine.exe". Obviously use the actual path for where it's located on your system.

It is likely Steam has by default made the "Start In" value the same as the game's .exe, so you might just have to remove the "bin" form the path.

Also if you have a working shortcut for the game somewhere that will have paths you can copy.

...PS, this is something that can potentially happen to any program/game so worth keeping in mind for future.

....PPS, this problem/solution would also apply to any standard windows shortcuts.