authentication failed miss user’s response

Hi everybody, i hope you are great.
I need your help, 2 days ago some guy was working in my website, making a design, but yesterday i tried to login but i couldn’t, a message “autenticacion fallida falta respuesta del usuario” “authentication failed, miss user’s answer”.

i tried to replace pass word by mail, it didn’t work. Then i tried to modify pass words in wp-users, on Cpanel, but it didn’t work.

i tried to desactivate plugins he had installed, but it just dindt work, He was designing a private page with users registration plugin, and he instaled mailchimp too.

I don’t know what happen and he says he doesn’t know neither.

Can somebody help me, I will appreciate your help

The page I need help with: [log in to see the link]