RC 5.4.8: Web UI not loading after OAuth login due to "uncaught promises"

Description:

I have a custom OAuth implementation. After logging in on the auth provider, I get redirected back to RC and hear the welcome sound, but I only see the three animated dots and do not get a chat interface.

Reloading the chat fixes the problem.

Steps to reproduce:

Not sure if this is reproducible with a plain RocketChat outside our special setup.

1. Have a RocketChat instance with a custom OAuth provider (PHP-based, using league/oauth2-server as the base)
2. Open the chat, click the button "Login via "
3. Log in with the identity provider, get redirected back to the chat
4. See the chat open, but breaking with the three animated dots
5. The browser console shows uncaught exceptions in promises:

Expected behavior:

Chat opens normally.

Actual behavior:

Three animated dots, in the console I see uncaught exceptions within promises.

I tried tracing the exceptions to their unminified source, and I think it's these two places:

• https://github.com/RocketChat/Rocket.Chat/blob/cda0b40a3cea996f8a2f11723883f53ea44d6714/apps/meteor/app/notifications/client/lib/Notifications.js#L83
• somewhere in Meteor, in some part called "rocketchat:streamer"/client. The error occurs in in the subscribe() method in there:
  
  I could unfortunately not find hat place within the code; I could, however, get the (probably not really helpful) stack trace from Chrome, see below.

Server Setup Information:

• Version of Rocket.Chat Server: 5.4.8
• Operating System: Ubuntu w/ Docker 23.0.3
• Deployment Method: Docker
• Number of Running Instances: 1
• DB Replicaset Oplog: Enabled
• NodeJS Version: 14.19.3
• MongoDB Version: 5.0.16
• Commit Hash: cda0b40a3c

Client Setup Information

• Desktop App or Browser Version: Firefox 112 and Chrome 10x
• Operating System: Ubuntu 22.04

Additional context

Relevant logs:

Stacktrace from Chrome for the rocketchat:streamer error:

onStop @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1458
_livedata_nosub @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1366
onMessage @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1366
(anonymous) @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
forEachCallback @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
socket.onmessage @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
r.dispatchEvent @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
k._dispatchMessage @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
k._didMessage @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336
o.ws.onmessage @ 63326d8399da4bede896e472cb4d732145c62c84.js?meteor_js_resource=true:1336

Start with apps/meteor/app/notifications/client/lib/Notifications.js at the referenced line, then trace the client rocketchat:streamer subscribe() failure using the browser console and stack trace. Reproduce the custom OAuth redirect if possible; done means the chat interface loads normally after login without uncaught promise exceptions.