Is your editor expecting two clips to create the transparency? One for the alpha and one for the fill? I'm staring at my Avid right now, and it imports clips with straight alpha channels just fine.
OK, here’s an update that solves my problem for now. I had been rendering my animations using the Avid Codec, DNxHD 110, with alpha channel set to uncompressed and straight. I thought that would make smaller file sizes, and allow the editor to import the graphic clips faster, since that was the resolution he was editing at. I had installed the Avid Codecs from directly downloading them from Avid’s website, a few months ago.
But I did a test, figure out why this was not working. I re-rendered a clip in After Effects, and used the Animation Codec, with alpha at straight. When we imported that into Avid, it worked perfectly. So, it seems that Avid’s own codecs are screwed up. Bizarre.
Not only did the Animation Codec import perfectly, it imported way FASTER than the same clip rendered in DNxHD. For a 10 second clip, the Animation codec took 40 seconds to import. And the DNxHD clip took a minute. So this was a surprise. I always thought the Avid codec would import faster, but it does not. And it reversed the alpha channel!! Thanks for nothing, Avid.
Thank you for trying to help. I’m suspect a lot of AE artists will have to deal with this, I hope this helps.
Thank you for reporting back with what worked for you.