If you are using an AT&T Email.you might get an error "LaunchEmptyResponse" but you need not panic as this error is caused by heavy traffic on the network also they're resolved automatically sometimes.if not then you can try the following steps:

1. Sign out of AT&T email from all devices and programs.
2. Clear your browser's cache and cookies.
3. Restart your browser.
4. Sign in to your AT&T email account. for more solutions visit  AT&T Email Support