Unable to Upload mp4

Just ran across this and not sure if it's an error or if I'm doing something wrong.

Trying to upload an mp4 manually from my computer into the uploader. After it finishes loading it gives an error message:

"Upload failed: File is not an image or video."

For context if that's necessary, tried to upload a longer, uncensored version of post #5779009 (nsfw). The artist had it as a limited timed free gumroad download so I figured it was fair game.

Post it on https://catbox.moe so I can take a look at it.

it's HEVC

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '[FishSyrup] Koyanskaya of Light (FateGO)[??????] Animation.mp4':
  Metadata:
    major_brand     : iso4
    minor_version   : 1
    compatible_brands: iso4hvc1iso6
    creation_time   : 2022-10-27T15:23:09.000000Z
  Duration: 00:01:00.00, start: 0.000000, bitrate: 4072 kb/s
  Stream #0:0(und): Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv), 2072x13
68 [SAR 1:1 DAR 259:171], 4069 kb/s, 30 fps, 30 tbr, 30k tbn, 30 tbc (default)
    Metadata:
      creation_time   : 2022-10-27T15:23:09.000000Z
      vendor_id       : [0][0][0][0]

I wasn't aware that hevc was an unsupported format.

That being said, if you still want to look at it evazion, here's a link: https://files.catbox.moe/mo6lhh.mp4

EDIT: Although now that I try to look at the catbox link, it doesn't work there either.

Grahf said:

EDIT: Although now that I try to look at the catbox link, it doesn't work there either.

From what I gathered (like here), most browsers either don’t support HEVC at all or only partially. So even if you could upload the video here, almost nobody would actually be able to view it.

Can I Use? has a more easy to read representation of support for HEVC.

The site may or may not support the format for e.g. thumbnail generation yet, but is it a strict requirement that they be viewable client-side? SWF isn't supported these days either and it doesn't affect that people can still download them here, so why not the same with files that you can play in an external video player but not in your browser? APNG wasn't always supported well either.