We recently migrated to GitLab 8.9 / Mattermost 3.1, and one of our users discovered that he was unable to log back in. Turns out he had never moved his account off of email sign-in, and since I had disabled email sign-in (allowing only GitLab SSO), he was now unable to log back in.
I re-enabled email sign-in so he could get back in and change his Sign-in Method under Account Settings > Security. He reported that this option does not appear for him. Confused, I logged in myself and checked the menu - sure enough, I do not have a “Sign-in Method” option available, either.
I have reloaded the page, cleared cache, tried different browsers, restarted the Mattermost service itself, and even run a gitlab-ctl reconfigure, but to no avail. The “Sign-in Method” is simply not available under Account Settings > Security, and users are thus unable to change their sign-in method.
Any help would be greatly appreciated.