Broken QuickTime Animation exporting

[Sperbus]

1. After Effects Version 23.1.0 (Build 83) / Media Encoder Version 23.2.1 (Build 2)

2. macOS Monterey version 12.6, Mac Studio 2022

3/4. I'm trying to export some short, simple animations with transparency, but something about the animation compression is severely broken. The Format is Quicktime, codec is animation, max render depth, 8-bpc + alpha, max render quality. It exports as a file unrecognizable to QuickTime, and when opening it in VLC it's off color and choppy (gif and exported video attached). Other video codecs (Apple ProRes 422 and the like) seem to work just fine, but I want to export lossless movs.

[Thaumar]

Legacy QuickTime codecs have been fased out for a while now. Animation (and others like P-jpeg and M-jpeg) codec is effectively unsupported today and basically just a relic of ancient QuickTime history.
You could use Prores4444 which supports alpha and has also a higher bit depth, so when rendering at 'max render depth', more information will actually survive the encoding. Animation was restricted to only 8-bit per channel.

Be advised, make sure to turn off hardware acceleration in the after effects import preferences pane, as the Apple Silicon M1/2 ProRes hardware acceleration implementation from Adobe is not working properly at the moment (greenish flickering).