There could be some possible reasons behind the log in issue. Basically, users Can’t sign in to Yahoo mail due to the following reasons:

1. Using incorrect yahoo login details either username or password
2. The user forgot the Yahoo login password
3. Invalid username or password issue message due to caps lock on or off
4. The yahoo sign-in button is not working or other browser cache related problems
5. Yahoo mail server has an issue or yahoo login server is down

There are some causes that may face your Yahoo email access. Now let’s go ahead and follow the steps given below to solve the issue.

To learn more details, visit here: How to Login AT&T.Net Yahoo Email?