The game worked fine before numerous times but when I went back to play today the game won't open and gives me the message I wrote in the title.

I'm using Vista Home Edition.

If there is a easy solution to this, please let me know. Thanks.

There's a couple of things you could try out.
1. Have you tried to run the executable inside the Sanitarium folder instead of the default GOG
wrapped one?
If not, try to run it, if it works make a new save and try to run the default GOG wrapped executable again.

2. Is the game installed outside the default "Program Files" folder?
If not, install the game outside this folder (e.g. C:\Games\...).

Hi!

Same problem here. Tried everything and have now surrendered to Virtual PC 2007. Installed XP on it and guess what? The issue remains. So I'm pretty sure it's not a Windows 7 only issue. Any ideas what might cause / fix this?

Same here. It's not the end of the world to just save regularly and seems to become more stable with time... It's good general adventure-game practice to get used to in any case, a game can crash for any number of reasons.

if that happens best thing to do is uninstall the game leaving the save game intact and reinstall the game it fixes it every time for me been having that problem with the hard copy of the game since it came out

I'm replying to an old message I know, but I just installed Sanitarium, and I think I had the same error when trying to launch the game.

In my case, the fix was to go to Sanitarium shortcut properties => compatibility, and enabling "Run this program as an administrator". After that the game lauched and ran fine. I've now played somewhere to 2nd chapter without issues.

Specs: Lenovo ThinkPad T400 laptop, Windows 7 64bit.

So could it be that for some reason that compatibility flag was accidentally removed from your game, hence it didn't work anymore? Then again, in my case it wasn't there after installation, I had to go enable it.

Installing this worked for me on Windows XP:

http://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=29

Executing it as administrator worked for me