since updating to Corona 15, render passes from Backburner are no longer saving out. When we downgrade back to Corona 14 or using another render engine, the passes save perfectly. I tested in Max 2024 and 2026. Only works with a version lower than Corona 15.
I also compared the settings between both the 14 and 15 version. Which are identical.
I tried to reproduce this issue on my end but I was unable to get the same problem. I started a ticket #493753 with you so we can further investigate this issue.
I’m having the same problem when using batch render; it’s supposed to save each element using the filename I specified, but it doesn’t save any of them. Try using that method. I had to revert to version 14.