As a general solution, consider running Steam integrity check. It won’t remove any new cars or tracks you might have installed, would only revert changed Assetto Corsa files back.

Can’t find “\python33\PyObject_CallFunction”

Make sure you have Microsoft Visual C++ 2010 Redistributable Package (x64) installed (direct link). If it’s already installed, reinstalling it can help too.

Image is flipped or split into two massive triangles which are flipped

If you’re using AMD GPU card, make sure to enable “Resolve MSAA for color” in Extra FX settings.

Message “GPU May be overheating or overclocked”

Disable “Use DXGI Flip Model” in General settings of Custom Shaders Patch.

Slight flicker of some parts of a track or car

Disable “Use proper physically-based sampling” in Reflections FX module.