If you're doing that already, and getting black backgrounds anyway, it's because your alpha pipe is broken on the color page make sure that the last node's alpha output (blue square) is wired to the master alpha output. So, make sure you're exporting to a format that supports transparency if you need it, like prores4444.

It'll just do what it's told, and then you'll wonder why your backgrounds are black instead of transparent.

It won't give you an error, or a warning, or recommend a different codec. It doesn't pre-suppose that you 'meant' to include an alpha channel because your source sequence contains one, but your chosen export codec doesn't support it. Resolve doesn't 'think' for its users the way some apps do. You do need to be careful with the way you handle transparency if you expect to use it. To enable Power Bins, on the Media page, go to the 'View' menu, and near the bottom of the list, check 'Show Power Bins.' If your media pool and/or media folders sidebar list is not visible, hit command-1 (mac) or control-1 (pc). From there, all you need to do is drag it to your Power Bin. One quick tip for the Export->Re-import step: After you export anything in Resolve, after Resolve marks the Queue item 'Complete,' You can right-click on the complete item, and select 'Reveal in Media Storage.' Resolve will then open the Media Page, and highlight the file in the browser. Export what you need on the Deliver page, Re-import it, add it to the Power Bin, and you should be good to go. Whether your image is static or animated an exported still image, file sequence, or video is compatible with power bins. However, in your case, a workaround is fairly straightforward.

Unfortunately, as of version 16.3, Resolve won't store Compound Clips, Multicam Clips or Fusion Clips inside a Power Bin. In Resolve, 'Power Bins' are what you use to make elements available across projects.

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