Can't launch the game

[Vylsain]

Steam cloud is activated.

Ok, gentlemen. Not really a problem. It is a security issue.
Once you get the zip file BEFORE extracting it, right click on it, go properties and click UNBLOCK.
Then extract and proceed as normal.

It's about the patch I presume. The problem is that it doesn't work even with the basic version, just after installation...

It's weird ! It was working well and someday, not even after a patch installation, it didn't launch anymore...