Updated: April 26, 2019
Speed. Or at least, there used to be. A couple of years ago, I bought Assetto Corsa, a really cool racing simulator. Impressed by the physics and driving dynamics, my finances dropped some when I bought a G27 wheel to go along with the game. Many hours were spent perfecting the line going into this and that turn, including me favorite track, Spa-Francorchamps. At least, this used to be the case.
Recently, I encountered a problem. Whenever I'd click the 'Start engine' button, which takes you from the main screen and into the actual game, Assetto Corsa would start loading the splash animation and then go back. The racing part would simply not launch. So I set about debugging.
Check the oil, check the errors
Well, my instant hunch was that the problem was entirely game-related - because the specific system had not changed at all, including the drivers. But somewhere in between one or two game updates, something went wrong. To troubleshoot some more, I decided to check the logs:
"My Documents"\Assetto Corsa\logs
There was a whole bunch of errors here. Weird things about shaders and this and that DLL. At first glance, stuff that doesn't really tell you anything about the game. And if you search for these online, my oh my, you will get a thousand different entries, each pointing to a subtly different scenario. Therefore, I decided to be methodical and as generic as I could.
Check game files integrity
Steam lets you verify your local files installation for errors. Right click on any game title > Properties. On the third tab 'Local Files', click on Verify integrity of game files... This launched a window, and I let Steam be. After about ten minutes, it informed that some 2,700 files were corrupted and needed to be re-downloaded. After this, Steam grabbed about 850 MB worth of data. So there was something wrong with Assetto Corsa, but why, I have no idea. The system is all spiffy and whatnot.
Try again ...
This time, the game did work! And everything was fine. For a brief while. Then, one or two game launches later, the problem re-manifested again. I consulted the logs, and this time, it was complaining about DX11 not being found, which would something not being all cushty with the graphics drivers.
As the simplest solution, I downloaded the latest WHQL Nvidia drivers available for the system, and a reboot later, Assetto Corsa was running well. Since, I've had no problems, and this leads me to believe that the issue is resolved. And I refrained from any specific, hard changes to the game configuration. We're back in the game [sic].
If you're curious ...
Now, if for some reason you do want to tamper, this is the file for you:
"Steam install folder"\steamapps\common\assettocorsa\system\cfg\assetto_corsa.ini
Here, you can make a lot of changes, and really affect the game's behavior. But it's nerdy, developery stuff, so you're likely to cause more harm than good. My general approach is that one should never meddle with things like scheduling, memory management and similar, even if the game allows you to do so - and many an online guide point to as workarounds for game misbehavior, stuff like:
USE_TIMER_PROCESS=-1 ; -1=Automatic, no timer process for CPU with more than 2 cores, timer process for dual cores. 0=Always off. 1=Always on.
SET_THREAD_AFFINITY_MASK=0 ; 0=Windows scheduler will decide where to run the threads. 1=Main thread assigned to Core0, physics thread assigned to Core1
A few cool images, and we're done!
Alsa Sprach Zarathustra. Or translated, thus ended this little guide showing you how to fix your Assetto Corsa simulator. I do have to admit I've never had any game corruptions before, definitely never with Steam, and few if any games ever complaining about drivers. So this leaves a sour taste.
But if you can overcome the unnecessary problem, then you can go back to racing and having fun! The game falls back to the main screen? Check the logs first, there might be a trace of useful information there. See if you can fix the local files, and grab the latest drivers. After that, there's the wild wild west of configurations, but that's the wrong approach. Anyway, speed!