Anthony Harrison

Your output from AE is Prores 4444 with alpha? What are you trying to encode it to? What’s the goal? H.264 doesn’t support an alpha channel (https://www.digitalrebellion.com/blog/posts/list_of_video_formats_supporting_alpha_channels.html)

Nexrender actually outputs the default AE output module into a temp folder before running the post render actions. I'm not exactly sure where this temp folder is on a Mac...