Please look here for more detailed description:
https://forums.chaos.com/forum/v-ray-for-3ds-max-forums/v-ray-for-3ds-max-general/1135441-vfb-vray5-how-to-get-the-frame-number-automatically-noted
The frame number stamp (info) is broken.
I can’t find anymore out, from which frame a render was done.
Thanks
_Lele
2
This works for me with the most recent stable nightly with CPU, while it is broken for GPU (VGPU-5676).
Would you mind trying it?
It works fine with cpu on the release version 5.20.02; it’s only gpu which doesn’t 
That picture…is that the secret driveway leading to the Chaoscave?
_Lele
5
Ahahah, i was doing some quick test on selective DoF, i left the secret driveway leading to the Chaoscave there, my mistake! ><
Careless sure, but still tricky to locate, luckily 