Permanent white screen with disabled registration and identity server invites

[gabrc52]

Steps to reproduce

1. Host Element on a custom URL, say matrix.example.org
2. Set setting_defaults -> UIFeature.registration to false and disable_guests to true
3. A user who has not logged in nor registered their email to the matrix.org identity server receives an email invite to a room through the matrix.org identity server (copy the link saying "Join the conversation" and paste it in an incognito window)

For reference, the URL has a structure like https://matrix.example.org/#/room/%21roomid%3Amatrix.org?email=jack%40example.org&signurl=https%3A%2F%2Fmatrix.org%2F_matrix%2Fidentity%2Fapi%2Fv1%2Fsign-ed25519%3Ftoken%3Dlongstringofthings%26private_key%3Dbla&room_name=test%20room&room_avatar_url=&inviter_name=Gabriel%20R.&guest_access_token=&guest_user_id=&room_type=

In reproducing this bug, you could try visiting this URL directly.

5. Element redirects you to https://matrix.example.org/#/register with a white screen
6. Any subsequent attempts to use Element, such as manually navigating to https://matrix.example.org/ result in being redirected back to the white screen

Outcome

What did you expect?

I am able to use Element

What happened instead?

White screen. Trying to switch to a different URL has Element redirect you back to #/register

Operating system

macOS and Linux

Browser information

Safari and Firefox 119.0.1

URL for webapp

No response

Application version

Element 1.11.48

Homeserver

Synapse 1.95.1+jammy1

Will you send logs?

Yes

[weeman1337]

@gabrc52 Unfortunately I cannot reproduce your issue. Please update your issue with more information. If we don’t hear back from you in a week, we will close the issue as we need to be able to reproduce it before we can fix it.

Is there anything you configured on the server side? Can you provide the browser logs when you are on the white screen?

[gabrc52]

I've realized disable_guests also needs to be set to true for this bug to occur.

Could you try the following?

First, run Element under localhost, for example:

wget https://github.com/vector-im/element-web/releases/download/v1.11.50/element-v1.11.50.tar.gz
tar xf element-v1.11.50.tar.gz
cd element-v1.11.50/
mv config.sample.json config.json
python3 -m http.server

Then in config.json, set setting_defaults -> UIFeature.registration to false and disable_guests to true, i.e.

$ diff config.json config.sample.json 
12c12
<     "disable_guests": true,
---
>     "disable_guests": false,
38d37
< 	"UIFeature.registration": false,

Finally, open an incognito window and paste the following URL: http://localhost:8000/#/room/%21xxx%3Axxx.xxx?email=xxx%40example.com&signurl=https%3A%2F%2Fmatrix.org%2F_matrix%2Fidentity%2Fapi%2Fv1%2Fsign-ed25519%3Ftoken%xxx%26private_key%xxx&room_name=xxx&room_avatar_url=&inviter_name=xxx%20xxx&guest_access_token=&guest_user_id=&room_type=

Alternatively, visiting http://localhost:8000/#/register directly triggers the bug too.

Attempting to visit http://localhost:8000/ results in the same white screen:

As for the logs, this is what Element prints to the console: