Maintenance for the week of August 3:
• PC/Mac: No maintenance – August 3
• ESO Store and Account System for maintenance – August 4, 5:00AM EDT (9:00 UTC) - 4:00PM EDT (20:00 UTC)
Error 307 indicates you've been disconnected from the server for reasons such as a connection issue. When this happens, you should wait for a period of 15-20 minutes before attempting to login again.