Cannot join room from matrix.to link, "No known servers"

[Bubu]

Description

I tried to click on the link in this message and could not join the room this was pointing to:

https://matrix.to/#/!xYvNcQPhnkrdUmYczI:matrix.org/$DJYCtRsqEio-s577yqTZya4EfSnfenU_QIJZ6LYFzK4?via=matrix.org&via=feneas.org&via=maunium.net

This was the link I couldn't follow: https://matrix.to/#/!yjVgJUsMLYLAONsoii:jki.re/$ABrOfGufg7k0jRLV0MnVLUnD28BYWMFy51hai0SZunU?via=jki.re&via=matrix.org&via=kde.org

Version information

• Platform: desktop
• OS: Ubuntu 18.04
• Version: riot-web version: 1.5.6

[anoadragon453]

I've been recently seeing these links not working when you click them (leading to No Known Servers), however if you then add the via parameters manually to the URL and then try to join again it works.

Seems like Riot regressed at some point in extracting them from the URL when clicked?

[jmcph4]

Any progress on this? Experiencing the same issues currently with various matrix.to links (up-to-date Debian riot-desktop package).

[anoadragon453]

Any progress on this? Experiencing the same issues currently with various matrix.to links (up-to-date Debian riot-desktop package).

Can you confirm that when clicking the link, your browser is making a POST /_matrix/client/r0/join/{roomIdOrAlias} request without any server_name query parameters included?

If they are there and you're getting No known servers, then this is a server issue.

[deliciouslytyped]

If you find this issue because you can't figure out how to open a room link in element-desktop, look at #12879 .

[Bubu]

@alexrollin: this is the repository for element-web, android issues aren't tracked here.

[cdauth]

Is there any progress or any more info on this? I'm experiencing this when I'm trying to open a room from another server.

[aaronraimist]

@Bubu Can you respond to #11756 (comment) please?

[Bubu]

@aaronraimist I tried (re-) joining the TWIM room I linked in my original issue. This is going via matrix.to to element-desktop. At that point clicking the re-join button indeed still produces the "No known servers error message" and element-desktop indeed didn't include any server _names in the query.

Now pasting the second link into a room and clicking on it does allow me to join that room. I'm not sure if it maybe was formatted differently in the original message I can't reach anymore though.

(Edit: I also just opened element-hq/element-meta#986 for a related issue.)

[aaronraimist]

Interesting. I thought the first part might be caused by matrix-org/matrix.to#235 but it looks like that got fixed recently.

[aaronraimist]

I did a test using a test using a fake room ID (so I didn't have to keep joining and leaving a real room) and I did see the server_names being included in the join request. I opened https://matrix.to/#/!fake:example.com?via=example.com&via=example2.com&via=example3.com in my browser and then clicked on the continue button in matrix.to to open that link in Element Desktop.

Element sent /_matrix/client/r0/join/!fake%3Aexample.com?server_name=example.com&server_name=example2.com&server_name=example3.com to the server.

[Bubu]

I can confirm that your !fake:example.com link works correctly for me as well.

I would imaging that the different with the (old) TWIM room if from above is that I get dumped to this screen before I have a chance to click join. And then the via parameters are missing.

[anoadragon453]

If your homeserver is already in a room (i.e. another user on your homeserver already joined it), then you will be able to join that room through a room ID without via pointers. Otherwise, they are necessary as your homeserver needs to pull events from another server that's in the room already.

You can join a room via a room alias (#some-room:example.org) without via pointers, as the homeserver domain from the alias will be used to join the room via.

I can't reproduce the issue by clicking on the link mentioned in the issue description. Is anyone still able to?

To thoroughly test using Element Web (or Desktop):

1. Open developer tools (Ctrl/Cmd+Shift+i) in and navigate to the Network tab.
2. Paste the matrix.to link into a chatroom somewhere, send it, and then click the link.
3. If you fail to join the room, find the request for https://<your_server>/_matrix/client/v3/rooms/<roomId>/join under the Network tab. Right click that request and select "Copy as cURL" or similar.
4. Paste the results into an issue here. That will allow us to see what Element sent to your homeserver, and whether it was enough information to join the room with.
5. Type /rageshake into the message bar and submit a rageshake reference the URL of this GitHub issue, to give us an idea of why the client may have failed to give all necessary information.

[Bubu]

@anoadragon453 I can still reproduce the original issue, i.e. going via https://matrix.to/#/!yjVgJUsMLYLAONsoii:jki.re/$ABrOfGufg7k0jRLV0MnVLUnD28BYWMFy51hai0SZunU?via=jki.re&via=matrix.org&via=kde.org I eventually end up with the following error message from element-desktop:

MatrixError: [404] Can't join remote room because no servers that are in the room have been provided. (https://matrix.bubu1.eu/_matrix/client/r0/join/!yjVgJUsMLYLAONsoii%3Ajki.re)

The network request sent is:

curl $'https://matrix.bubu1.eu/_matrix/client/r0/join/\u0021yjVgJUsMLYLAONsoii%3Ajki.re' \
  -H 'authority: matrix.bubu1.eu' \
  -H 'accept: application/json' \
  -H 'accept-language: en-US' \
  -H 'authorization: Bearer XXXXXXXXXXXX' \
  -H 'cache-control: no-cache' \
  -H 'content-type: application/json' \
  -H 'origin: vector://vector' \
  -H 'pragma: no-cache' \
  -H 'sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "Linux"' \
  -H 'sec-fetch-dest: empty' \
  -H 'sec-fetch-mode: cors' \
  -H 'sec-fetch-site: cross-site' \
  -H 'user-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Element/1.11.17 Chrome/108.0.5359.179 Electron/22.0.2 Safari/537.36' \
  --data-raw '{}' \
  --compressed

I think the issue here is that element interposes the "can't load timeline position" popup for me (as noted above) and at that point has lost the via parameters.

I'll send a rageshake. (Edit: sent)

Edit 2: No change with Element version: 1.11.20 btw. (the latest I currently get from my distro)