Please explain the problem in detail. What happens? What is the exact error messages?

Happened yesterday afternoon. I have 6 usernames(family) only one of which is working. I cannot sign into the other 5 usernames. Each time I try I am taken to AT&T sign in which I never used. Did not receive error message, one minute every thing worked nrxt I had the problem. I need to get to the other user locations. Since I cannot contact anyone directly about the problem I am basically shut down

Most websites only allow one open account at a time. Is that the issue? Have you tried signing out?

Only one account is open that is why I need to sign out of that user and go to another user account. I can't do that on Firefox as I always did by clicking on the user account I wanted to go to. I am now sent to an AT&T sign in. Is this an AT&T problem or Firefox??

Hi Hombart, do you mean your AT&T-branded Yahoo email account? Or did they choose a different partner for their email accounts?

Did you sign out first?

Spent 2 hours on the phone with AT&T , problem resolved. Thanks to all for your comments.

Good work. Could you please tell us how the problem was solved?