Perhaps the Windows Event Viewer can offer you some guidance.

If you don't get a crash window then it's probably a hardware conflict of some type, but again. The feature opens by default in the event it is needed to update the scene to a compatible ART or Arnold format (Physical Materials and. When opening a scene file with legacy plug-ins, such as Mental Ray or Iray, the 3ds Max Scene Converter automatically detects these components and appears. If you get a crash window submit it to Autodesk and they can tell you what module the crash was in if you post your submit # here and perform the ritual to summon an Autodesk employee mention). When opening an Iray or Mental Ray based scene file in 3ds Max, the Scene Converter opens by default. Most folks on the forums won't be able to repro your problem and without a supported installer version it's very difficult to help solve this problem.

Even NVIDIA won't be able to help provide support. I realize that I'm steering you away from MR and that's not what you want, but it's discontinued and it's time to upgrade your process. That being said you can still fake AO with a gradient ramp and a fresnel falloff with scanline in many cases. It's changed my life when it comes to texturing.

Or, I can't say enough positive things about Substance Painter if you haven't tried it yet it'll do what you're asking and way more. Usually a dome light and the default AO in any renderer will look good. AO's baking dirty is simply a function of sampling but it doesn't mean those renders are bad or anything.

Mental ray 3ds max 2020