Maintenance for the week of May 19:
• PC/Mac: No maintenance – May 19
• NA megaservers for maintenance – May 21, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC)
• EU megaservers for maintenance – May 21, 8:00 UTC (4:00AM EDT) - 16:00 UTC (12:00PM EDT)
• ESO Store and Account System for maintenance – May 21, 4:00AM EDT (8:00 UTC) - 12:00PM EDT (16:00 UTC) https://forums.elderscrollsonline.com/en/discussion/677862
As mentioned above, error 307 indicates you've been disconnected from the server, which can sometimes be for inactivity. When this happens, you should wait for a period of 15-20 minutes before attempting to login again. You are welcome to send in feedback on this error with a ticket here.