Password reset not working. Hard to find info

The password reset is not working at all. When trying to restore the password, it shows a no existing page. I don’t understand why.
Also, when some of affiliates try to register themselves, they don’t receive an email with the password, just a registration confirmartion email. It seems it is something related to WordPress already related to emails. I have tried with 2 different emails, one worked, the other one didn’t. To sum up, another time wasting plugin. I would tried the paid features, but how can I trust a plugin that do not work? What if an affiliate lose his password?