Unable to change other user passwords

I’ve got an app that uses User Engine. I can log in as the super user
just fine. If I attempt to change another user’s password, it doesn’t
seem to take in that I cannot log in that user with the new password. I
don’t have the old passwords, so I don’t know if it has been changed or
not.

How can I tell what’s going on?

SOLVED

I had made a bunch of test users. They all had the same e-mail address.
User Engine does not like that at all. I consider that a bug. I can
imagine scenarios (like maybe testing) where different accounts would
use the same address.

So, as long as all your users have different e-mail addresses, and your
passwords have the correct form (at least 5 characters), it seems to
work OK.

If not, it doesn’t work and doesn’t tell you why.