QuickTime Rendering for a Transparent background

[uglyhudson]

So I'm using a MacBook with os Catalina version 10.15.1 and I'm trying to render a video on after effects & media encoder using the QuickTime GoPro+alpha channel so I can have a transparent background, but due to apple not supporting quicktimes codecs anymore the render will not play. I've tried using VLC to open the rendered video and that doesn't seem to work either. Is there any other way I can render a video with a transparent background using a different setting or file type?

[Rick Gerard]

I use GoPro Cineform all the time but I'm not on Catalina because one line of 32-bit code in an app or an extension will kill the process. When you say the rendered file won't play do you mean in the Quicktime Player or do you mean the file won't work in AE or Premiere Pro? You could try ProRez 444. That supports Alpha Channels and should work in Catalina. There is always an image sequence. 

What is your complete workflow?