I am using Meta Quest 3.
can’t play SBS videos with the VP9 codec on HereSphere 0.10.1 that I purchased from the META site. However, I was able to play videos with the AVC and HEVC codecs.

When I try to play it, the format part does not display as VP9 and the video does not play, it remains blank.

I think Quest 3 might have an OS issue where VP9 over 4k doesn't work. Not sure what's causing the issue. Quest 2 seems to handle it fine. HS uses the codecs included with the OS, so Meta probably needs to fix it on their end.

I’ve tried various local players, but indeed, all of them give an error and can’t play the video :/
If necessary, I can send the video file to you.

I don't think I can fix the issue on my end, since it's most likely an issue with the Quest 3 OS or hardware. Your best bet is transcoding the video to another codec (h264, h265, or av1). FFmpeg can do this. Or use the PC version of HereSphere and stream PCVR using Airlink, Virtual Desktop, or Steam Link.

I encountered the same issue and found it has been reported to meta support https://communityforums.atmeta.com/t5/Get-Help/Quest-3-cannot-play-VP9-codec-vid...