Both Apple TV and iOS affected for me. I had to rebuild all metadata to get it fixed.
Mac 8.4.3 also crashes when trying to add to a playlist.
Can you describe where you are seeing these black posters?
The 8.4 update added some new metadata and artwork related settings, so you may check to ensure these are set to match your preferences. These can be found in Infuse > Settings > Metadata & Artwork.