A weird issue just popped up for me when I suddenly couldn't render any of my pyro setups (I just get black screens). So I opened a brand new hip file and created a very basic sparse pyro setup. I used a DOP Import Fields and import the fields I need. I hooked up the Pyro Bake Volume, and the pyro shows in the viewport, but it doesn't show up in the render.

I have the hip file attached. Can someone please put their eyes on it and see if I'm missing something?

your density is empty, and density is used by default for culling of empty voxels

- so while you could delete density volume and it would render, it would not be optimized
- slightly better would be to fill density with tiny values everywhere where flame is >0, but that would still be unnecessary workaround

- the best way is to add add vm_volumesamplingchannel property to your geo and set it to: flame
so that flame volume is used for voxel culling instead of density