Clicking edit button on Domain Verification page results in 500 error

https://sentry.gitlab.net/gitlab/gitlabcom/issues/4134005/?referrer=gitlab_plugin

NameError: undefined local variable or method `group' for #<ActionView::Base:0x00000000688d50>
Did you mean?  @group
  app/helpers/application_helper.rb:467:in `gitlab_ui_form_for'
    form_for(record, *(args << options.merge({ builder: ::Gitlab::FormBuilders::GitlabUiFormBuilder })), &block)
  app/controllers/application_controller.rb:144:in `render'
    super.tap do
  app/controllers/application_controller.rb:500:in `set_current_admin'
    return yield unless Gitlab::CurrentSettings.admin_mode
  lib/gitlab/session.rb:11:in `with_session'
    yield
  app/controllers/application_controller.rb:491:in `set_session_storage'
    Gitlab::Session.with_session(session, &block)
...
(245 additional frame(s) were not displayed)

ActionView::Template::Error: undefined local variable or method `group' for #<ActionView::Base:0x00000000688d50>
Did you mean?  @group

Zendesk ticket (internal link only)

• User has connected a project
• User has added txt record to DNS zone

Another report of 500 error in this Zendesk ticket (internal link only)

Unsure if it's only manually added domains.

Behaviour

The domain verification entry cannot be edited. Edit button throws a 500.

On an entry in project (ID: 44213270), threw 500 on Edit, but no issues with Delete.

Likely only verified domains. No issues with an unverified domain.

Workaround

In these cases, cannot be edited. They can be deleted and a new verification can be deleted, but then the TXT record needs to be updated.