This error message also relates to ERR100, ERR101, ERR125, ERR136, and ERR140.
You'll get the GAH! ERROR 2 message if there's a mailbox connection problem. Usually, this error will resolve itself if you wait a few moments and then reload your mailbox. If this doesn't immediately work, there are other steps you can take to fix the issue.
Restart your browser
Sometimes the old "turn it off and on again" solution actually works! Just quit your web browser, and then start it back up again. Once the browser has been restarted, go to mail.aol.com and enter your username and password.
Clear your browser's cache
Another way to fix these error messages is to clear your browser's cache. This will wipe out all the little unwanted bits of info that have been stored in your browser, making it run better overall.