This game has a terrible optimization so it's unfortunately normal for such graphic card

It is TexAtStart line in General.opt. It should be 0.
Can't understand why the community should do it and not the developers... Such a brilliant game and such a shitty performance.

I've discovered the exact setting causing the whole issue! It's "Textures initialized" . When it's ON you can't run the game without a message error.

I've found what causing the issue. It's a setting file. Every time you change something in the settings game works unless you exit. Then it doesn't work unless you check the integrity of game files again. So when the game opens again you can find that all settings are default. Still trying to figure...

I'm still trying to figure it out.

I don't know whether it could help somebody in future but I had the same problem almost every time I tried to launch the game. I found the only cure for steam version that works every time - checking the integrity of game files. When you launch this option steam finds one mysterious file to download...