Updating Instances Increases Render Time with Motion Blur

[djanim8]

I have a scene I'm working on that takes 40 seconds to render normally, but when I turn on motion blur on the physical camera, the render nearly gets stuck on "Updating Instances". I let it go and after 30 minutes I gave up. I have the same objects in a different file with motion blur and I don't have that problem. I've searched but haven't found a solution. I restarted max and I have no displacement modifier in the scene.

I'm using Max 2019 with the vray_adv_62007_max2019_x64 nightly stable build.

Does anyone else have this issue?

[Philip Shounev]

Hello,

Mind if you send a scene sample to philip.shounev@chaos.com so we can investigate further what's causing this slowdown?

[vladimir_krastev]

Hi, thanks for posting. Have you tried to reset your render settings to default? Have you tried to merge your scene into a new empty scene?
Please test these steps and share the result.