I'm on 3.08 for R17, and can't get vdb clouds to render in the C4D picture viewer, but they show up perfectly fine in the Octane live viewer window. I've also tested with 3.05 and separately with R19 and same issue persists.
I know for a fact it's not my vdb paths, as they are correct and point to local drives. Also have scene geometry set to all under Octane Settings in C4D window, tried Octane object tags on the vdbs but that didn't work either, no slaves being used.
What gives? Not sure what else to try, never had this issue before.
Here's some pics of my vdb settings: