Transforming Vertices hangs, but only for CPU buckets

V-Ray V-Ray for 3ds Max General
1

I have a fairly big scene using tyflow and forest pack but even stripped down the CPU hangs on transforming vertices, I havn’t been able to get a render out yet, i have been isolating objects trying to find the cause. I built the scene in GPU mode then realised vray GPU doesn’t support forest pack very well. So i switched to CPU and it hangs to the point where i have to crash the software everytime. I have removed all plugins. all materials. i have merged the scene into a new. funny thing though, IPR CPU works, and GPU IPR and bucket. but not the CPU bucket. any ideas?

Tested in 3ds max 2020 & 2022 with Vray 5 2.2
32 core threadripper
2080TI
128gb ram

2

Okay i have figured out the problem, and its not vray specific, i tested in arnald too

Its the physical camera. I rotated the scene and camera by linking them to a dummy object and turning it 90 degrees, I had only ever used GPU rendering which works fine, but vray and Arnald cpu both freeze/crash when rendering through that camera. such a weird bug i will send it to autodesk