Backburner Rendering - No image preview?

[jms.lwly]

This morning I've sent a couple of images to render on another machine, and the frame buffer isn't showing any preview of the render (I understand that it won't display it in the Corona VFB, but even the Max frame buffer is blank). Shows a black image, with a small square of grey in the top left corner (see attached).

The eventual render output (a CXR and some Tiffs for posterity) were all totally fine and looked exactly as expected...

Just opened a different scene, sent that to Backburner and had the same thing happen - any thoughts?
I've been using Corona with backburner for several years and never had this issue previously.

[joonior1985]

Hi there,
any progress or clues there? I started a new topic some time ago with the same issue: https://forum.corona-renderer.com/index.php?topic=30872.0
Funny thing is my friend called me today and asked me if I did encountered black framebuffer when sending jobs via backburner.

Cheers!

[jms.lwly]

No progress for me (original poster) - this sometimes happens and other times the Corona VFB appears fine on the backburner machines...

There doesn't seem to be any pattern or reason why it works as normal or sometimes appears as black (in the default Max framebuffer).

[PeterSi]

Hi:)
We have same problem on corona 6 (corona 5 was working ok). It only appears when we are using render node licence. On Workstation licence this problem does not occurs. We  are using  max  2020.

[maru]

I have sent out a short survey to the users experiencing this issue. The goal is to find out if there is some kind of pattern here - e.g. same software or hardware.
If you are experiencing this (when using Backburner, the 3ds Max native VFB is visible instead of the Corona one, and its content is black), please send me a PM here or to miodek@corona-renderer.com and I will send you the link to the survey.
I do not want to share it publicly to prevent SPAM / false answers.
Thanks in advance!