Problems showing Image

[yncyrydybyl]

Steps to reproduce

Upload a picture.
Look at the timeline.

Outcome

What did you expect?

I expected to see the picture in the timeline.

What happened instead?

I see "Error downloading image" in the timeline.

For https://element.ems.host/_matrix/media/v3/download/element.io/f9921a8d3df6e4f31f53857644245a8bf54361ae1892570265175457792?allow_redirect=true

i get a:

{
    "errcode": "M_NOT_FOUND",
    "error": "authentication is required to download this media",
    "mr_errcode": "M_NOT_FOUND"
}

And the status code is a 404.

Operating system

Linux

Browser information

Version 132.0.6834.159 (Official Build) (64-bit)

URL for webapp

https://chat.element.io

Application version

Element version: 1.11.92

Homeserver

element.ems.host

Will you send logs?

Yes

[t3chguy]

Version 132.0.6834.159 (Official Build) (64-bit)

What browser is that?

Will you send logs?
Yes

Not seeing any logs from you

[yncyrydybyl]

Sorry. Its a chrome.
I dont have access to the server logfiles. But will send a ragshake now.

[t3chguy]

Unfortunately your logs do not shed any light on why the service worker isn't working as expected, there's a separate issue which means we don't get logs from the service worker in rageshakes.

[yncyrydybyl]

Maybe it is worth noting that i run at least 3 sessions of element-web in the browser since it was not possible to have multiple tabs.

• https://develop.element.io
• https://app.element.io
• https://chat.element.io

[pini-gh]

Hi,
Same kind of error on our instance with dockerized element-web v1.11.94 and Firefox 128.5.0esr (Debian 12). We run a small instance (almost 5 years old) for our association and most accounts are local.

The behavior is confusing:

1. Someone upload an image into a room
2. I can't see the image but the message "Error downloading image"
3. If I reload the page with <Ctrl+R> the image appears
4. If I force reload the page <Ctrl+Shift+R> the error is back
5. goto 3.

When at step 4, if I scroll back into the room's history I can see the "Error downloading image" message for all images until late November 2024. Previous images are OK.

But this weird behavior is really new. I noticed it today, while I use Element almost every days and update at least once a month.

I tried reverting down to release v1.10.80 with no luck.

I can provide logs on demand.

[pini-gh]

With the "late November 2024" date in mind, I scrolled through synapse's release notes and this one rang a bell:

Synapse 1.120.0 (2024-11-26)
This release enables the enforcement of authenticated media by default, with exemptions for media that is already present in the homeserver's media store.

And per the related documentation:

enable_authenticated_media
When set to true, all subsequent media uploads will be marked as authenticated, and will not be available over legacy unauthenticated media endpoints (/_matrix/media/(r0|v3|v1)/download and /_matrix/media/(r0|v3|v1)/thumbnail) - requests for authenticated media over these endpoints will result in a 404. All media, including authenticated media, will be available over the authenticated media endpoints _matrix/client/v1/media/download and _matrix/client/v1/media/thumbnail. Media uploaded prior to setting this option to true will still be available over the legacy endpoints. Note if the setting is switched to false after enabling, media marked as authenticated will be available over legacy endpoints. Defaults to true (previously false).

And precisely:

• we didn't revert this new default setting and everything was working well so far, until a few days ago
• when trying to download an unavailable image there is a 404 error with a path starting with https://matrix.example.org/_matrix/media/v3/download/... (unauthenticated endpoint).

How should we proceed to make element-web use the authenticated endpoints instead?

EDIT: looks like #28370 actually.

[yncyrydybyl]

EDIT: looks like #28370 actually.

But it's not on FireFox it is on Chrome.

[Infinoid]

We've now started seeing this issue with the conduit homeserver's recent 0.10.0 release, where they refactored the media endpoints to require authentication for new posts.

They linked the matrix client-server API spec, which says:

By Matrix 1.12, servers SHOULD “freeze” the deprecated, unauthenticated, endpoints to prevent newly-uploaded media from being downloaded. This SHOULD mean that any media uploaded before the freeze remains accessible via the deprecated endpoints, and any media uploaded after (or during) the freeze SHOULD only be accessible through the new, authenticated, endpoints.

And those semantics are exactly what we're seeing here. We updated our homeserver yesterday. Media posted beforehand still shows up fine on clients using the unauthenticated media endpoints, new media does not. It looks like Cinny supports the newer media endpoints, and element-web does not.

Or is there a flag to turn on, or a bad feature negotiation or something?

UPDATE: It's fixed in our case; it sounds like a bad feature negotiation. Conduit 0.10.3 fixed it with the changelog "Conduit now will claim support for matrix versions up to v1.12, fixing Element's clients not using the authenticated media endpoints".