User can't login

[pizzafilms]

Hello,

Out of the blue, one of my users can't login. 

He's been an active user for the past 2 months. I got this from the user:

Got a message saying password/user name incorrect. I clicked on "reset password". 
Got an email link to reset it. Clicked on the link. Got to the page where I confirmed it was me. Got another email with a new password
(random string of numbers and letters). Went to the login page. Entered my email address
and the new randomly generated password. Got a new page saying "the password and user name are incorrect". Now all I get is that page
no matter what I enter.

Then I tried changing his password from the Admin panel and sent him that password. His still couldn't log in. 

I tried logging in myself as him, using his email and a password that I created and I get the same error.

Nothing has changed since I installed this bb last year.  We're running MyBB 1.8.7.

Any ideas?

Thank you.

[.m.]

have you tried using user name & changed password (from admin panel) to login ? if not then try it ..

[pizzafilms]

Yes. I changed his password from the admin panel and sent him the password. He couldn't login.

I also tried logging in has him with that new password and I couldn't login either.

[.m.]

^ would you like to PM me temporary access to your forum admin panel & that user's user name to check it