[Help] Can't launch session, error messages...

[AnthoM23]

Hello guys
First of all sorry for my english

It's been months now since i can't play AC because of a big problem that i can't find the solution and it piss me off that the nurb, dream pack comes soon and i can't get a taste of it.

Here's the problem : When i want to start a session, i get a black screen, then a crappy resolution with thoses error messages :

CreateTexture2D depthStecilTexture failed
CreateDepthStencilView failed
CreateShaderResourceView depthResourceView failed
CreateTexture2D KGLRENDERTARGET depthStencilTexture failed

And then i get back to the menu..

My drivers are up to date.
I already reinstalled the game twice.
I verified the Steam cache.

I hope to solve this frustrating error, that would make my day.

Best regards.