If I make a new scene and add a cube, it works like a charm, but on other scenes it crashes.
Also you may want to solve the whole Mental Ray crashing thing (unless you're planning on using a third party renderer) because it's much more powerful than the default Maya Software renderer. Does Mental Ray crash even if you make a simple polygon cube in a fresh scene and render? Check the crash logs.
The link which says "this article" doesn't work for me, but I assumed that it explained how to reset my preferences - I already did that but mental ray still crashes.
Try these options: https://knowledge.autodesk.com/suppor...rendering.html
The output data type "rgba_h" warning is harmless.
I reinstalled my whole Maya and still doesn't work
How about to redownload and reinstall the Mental Ray Package?
I kinda doubt that the problem is in my machine. I bought this PC 3 weeks ago. The specs are:
Hmm might want to run a memory test then. If you can, try one of the scenes that usually crashes on another machine.