Error decrypting video on some gifs/mp4s sent by non element users on various bridges

[gouthamravee]

Steps to reproduce

1. Where are you starting? What can you see?
   In chats with users who are not using Matrix/Element, bridged through Mautrix-Telegram or Mautrix-Whatsapp

2. What do you click?
   Non matrix/element user sends a gif or MP4

Synapse media size option is set to 50MB, file size is less than media size limit.

Outcome

What did you expect?

Element should show the media inline in the chat

What happened instead?

File is received by element says Error Decrypting video.

Operating system

Windows 11, Mac, Android

Application version

Element Desktop, Element Web, Element Android

How did you install the app?

From website and google playstore

Homeserver

Personal Synapse Home Server installed through Matrix Ansible Playbook

Will you send logs?

Yes

[t3chguy]

2023-08-21T15:18:38.436Z E Unable to download attachment to decrypt it:  MatrixError: [404] Not found [b'gravee.org', b'pEjGlFLDGrCsmQFMWcYIuzoo'] (https://matrix.gravee.org/_matrix/media/r0/download/gravee.org/pEjGlFLDGrCsmQFMWcYIuzoo)
M_NOT_FOUND: MatrixError: [404] Not found [b'gravee.org', b'pEjGlFLDGrCsmQFMWcYIuzoo'] (https://matrix.gravee.org/_matrix/media/r0/download/gravee.org/pEjGlFLDGrCsmQFMWcYIuzoo)
    at c (vector://vector/webapp/bundles/e1d4beacb839288093f6/bundle.js:2:1355935)
    at u (vector://vector/webapp/bundles/e1d4beacb839288093f6/bundle.js:2:1394613)
    at async s.getFn (vector://vector/webapp/bundles/e1d4beacb839288093f6/bundle.js:2:1300202)
    at async Promise.all (index 0)
    at async P.downloadImage (vector://vector/webapp/bundles/e1d4beacb839288093f6/bundle.js:2:2760248)

Looks like an issue with the event, likely the fault of the bridge or your server.

[richvdh]

Duplicate of #28060