It seems that i can't make it tonight. I got home couple hours ago and it seems that tha latest patches have made Assetto corsa unplayable for me some reason. I think i have to install the game and since i have kinda slow internet it's not really possible to do it before the race starts
Sorry to hear that mate hope you get it sorted soon.
With steam there is a validation check of your files
Right click on AC in your steam interface Library and click properties
in local files you can verify integrity of game cache.
this will replace any corrupt files.
it may help.