Using the free Moodle Cloud site, I have about 20 test users configured with email-based self-registration authentication. Despite not having a password policy and setting each of the user passwords to a very simple combination, none of them can authenticate. It just says "invalid login" --
I've checked carefully that I have their username and password correct, but no joy.
Any ideas where else I should be looking?
Most of these users could log in 90 days ago when I last tested something on the site with a group of students.
P.S. The link to the FAQ page in the pinned post in this forum goes to a dead link.
Hello Thom 
Hopefully one of the MoodleCloud team will be able to assist you shortly, but thanks for the heads up about the dead link - which I have just corrected.
Hi Thom, the issue was that the "email" auth method was disabled. When you disable an auth method that is currently in use by existing users, this prevents password changes (even though the user edit page gives no indication of this). I've sent you a PM.
Thank you, Cameron! I'm sorry to have not noticed that. I thought it was due to the fact that I hadn't logged into the site in a while... long enough to have gotten the warning notice of iminent deletion.