Maintenance for the week of December 23:
• NA megaservers for maintenance – December 23, 4:00AM EST (9:00 UTC) - 9:00AM EST (14:00 UTC)
• EU megaservers for maintenance – December 23, 9:00 UTC (4:00AM EST) - 14:00 UTC (9:00AM EST)
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.