Uploading video results in 503

[jakearchibald]

Steps to reproduce the problem

When I try to add the following video to a post:

out.mp4

This happens:

Then this happens:

This has happened often over multiple days.

Expected behaviour

The video is added to the post

Actual behaviour

503 message, and video is not added

Detailed description

No response

Mastodon instance

https://mastodon.social

Mastodon version

v4.6.0-nightly.2025-11-06

Browser name and version

Firefox 146.0a1

Operating system

macOS 15.7.1

Technical details

No response

[mjankowski]

Could be timeout during upload? Could be server-side processing issue?

Does this happen with other videos on your account (encoded/created same way), or just this one?

Looks like file size is JUST under the default limit, not sure if thats relevant re: processing.

[jakearchibald]

I had it happen with multiple videos. It could be a timeout. Is there a set time to upload the video?

[ClearlyClaire]

Oddly enough, I don't get a 503 but a 413 when trying to upload it on mastodon.social. A 413 is indicative of the upload being rejected for being too large by the reverse proxy rather than Mastodon itself, so it is a bit surprising that you hit a 503. But a 503 would be indicative of an issue with the Mastodon process itself.

We will see if we can figure out more information.

[jakearchibald]

Yeah, I'm getting a 413 now too, but I was seeing the 503 over multiple days.