If you receive an Error 307, you have been disconnected from the megaserver. If this occurs to you, you may not be able to log back in immediately (resulting in Error 304), and we recommend you wait for period of 15-20 minutes before attempting to do so.
If the issue persists and you are not able to log back into the game, check the Service Alerts page to see if ESO is experiencing an outage or going through maintenance.