Similar problem but was not messing with admin settings. I had just updated a lot of products and logged out. Next time i try to log in and enter admin/pass and click to log in, it just clears the fields but does not log me in.
I tried the "resend pass" option. When I enter the email and click it just clears the field but I never receive any email with the password.
I will try to use the SQL method to reset to temporary password but wondering still...why would an functional log in just decide not to work?
:blush: