[b-kandor]

All my instances are black in the custom alpha.

[b-kandor]

Weird, I converted all instances to mesh and it's the same problem. The black part seen below is selected in the custom alpha channel.

[dariolanza]

Hello b-kandor,

I'm trying to replicate your situation but not getting any error.

All my instances here appear white in the Alpha channel like any other regular object, as expected.

Can you check in a very simple scene (with just a couple of objects) just to try to narrow where the issue could be?

Keep me informed about this issue.

Greetings

Dario Lanza

[b-kandor]

It appears it wasn't instances but groups. So, objects that were in groups even though they appeared in the list were being ignored. I fixed that file by ungrouping everything.