OGRE EXCEPTION(3:RenderingAPIException): Cannot create device! inD3D9Device::createD3D9Device
at ..\..\..\..\..\RenderSystems\Direct3D9\src\OgreD3D9Device.cpp (line707)

What should I do with this?
I can't start the game.

Did you start the configuration tool? If not, do it.

Is it the thing I use to change language and stuff?
If so, I can't open it either. same error message shows up.

Are you drivers up to date?
And yes, the config tool is the window to change the language and stuff.
I suppose you are trying to play in Steam?
Die you ever manage to start the game (or config tool)?

I used to be able to start them but at some point I can start neither of them.
Drivers... NVidia drivers? I always update them.
Yep I bought the game on Steam

Hmm. Usually a reboot helps but I guess you have done that already. Also sometimes it just fixes itself for whatever reason.
Did you try reinstalling it?

I haven't but I'll try.
Thanks for the suggestion.

EDIT:
It worked thanks for the help