I just got the game today, do I need to install the patch because when I try to it says 'Game Installation Not Found'.

Don't have this game on GOG, but generally, if a patch has lower number than game installer, you don't need to install it, cause it's for older versions.

I get the same error message with the current patch (patch_1954_alcatraz_2.0.1.3.exe). The game (setup_1954_alcatraz_2.1.0.4.exe) without the patch displays version 1.3.5019 on the option screen .

Can someone from GOG confirm that this is the latest version?

If yes why offer the update? Also the error message shoud be changed to something like "The game is already up-to-date.".

I also get the "Game folder not found" message, and I think the reason is that I did not install the game on my C:/ drive, but on my D:/ drive, and the patch installer is looking for the game on my C:/ drive..... so unless I uninstall and re-install on the C:/ drive, I will not be able to patch the game..... So this is another game from GOG that will not get played on my setup, because I will not install any games on my C:/ drive!