"Unable to get validated threepid" error when registering

[dbkr]

Steps to reproduce

1. Fill in registration form with hs matrix.org, supply an email address
2. Click Submit
3. Complete the captcha
4. Agree to terms
5. Land on the screen telling you to check your email

What happened?

After a few seconds, a red error message appears saying, "Unable to get validated threepid". It's just cosmetic though - registration works fine if you click the link in the email & carry on.

What did you expect?

No error message

Operating system

No response

Browser information

No response

URL for webapp

No response

Homeserver

matrix.org

Have you submitted a rageshake?

No

[kittykat]

I had this yesterday as well

[anoadragon453]

This is what it looks like:

It's coming from the server, and Element Web is surfacing it.

Response JSON

// GET /_matrix/client/r0/register

{
  "session": "xxxxxx",
  "flows": [
    {
      "stages": [
        "m.login.recaptcha",
        "m.login.terms",
        "m.login.email.identity"
      ]
    }
  ],
  "params": {
    "m.login.recaptcha": {
      "public_key": "xxxx"
    },
    "m.login.terms": {
      "policies": {
        "privacy_policy": {
          "version": "1.0",
          "en": {
            "name": "Terms and Conditions",
            "url": "https://matrix-client.matrix.org/_matrix/consent?v=1.0"
          }
        }
      }
    }
  },
  "completed": [
    "m.login.terms",
    "m.login.recaptcha"
  ],
  "error": "Unable to get validated threepid",  // here
  "errcode": "M_UNAUTHORIZED"
}

This LoginError was actually added recently in Synapse v1.42.0, via https://github.com/matrix-org/synapse/pull/10561/files#diff-f3cd2df66d514365038de3c9a6f15f1324ac34815c67209e09a63bac60f1acb4R196-R198.

I think in this case Element may just want to refrain from showing error messages on this page where we expect to receive M_UNAUTHORIZED responses as part of normal operation.

This may also be a problem on the Element mobile clients, but I have not checked.

[Soundtoxin]

I hit this as well when registering for boba.best via their hosted Element instance. I registered from qutebrowser on GNU/Linux, although my useragent is set to Firefox.

[kittykat]

Feedback from the community testing session was that most (seasoned Matrix) users found the message a little alarming and very confusing.

[t3chguy]

I think in this case Element may just want to refrain from showing error messages on this page where we expect to receive M_UNAUTHORIZED responses as part of normal operation.

This is a functional proposal, but it feels like it might also catch genuine errors and prevent them from being surfaced.