Maintenance for the week of April 15:
• [COMPLETE] ESO Store and Account System for maintenance – April 16, 8:00AM EDT (12:00 UTC) - 6:00PM EDT (22:00 UTC)
After receiving Error 307 you may need to waiting 15 to 20 minutes before being able to log in again. You can also check the Service Alerts page as there could have been a temporary outage.