We are scheduling system maintenance on:

Date: January 15, 2018
Time: Between 5:00 - 7:00 UTC
Aim: Server maintenance
https://www.timeanddate.com/worldclock/fixedtime.html?msg=Backlog+Maintenance+Time&iso=20180115T05

All users will not be able to access your Backlog. We appreciate your patience and sincerely apologize for any inconvenience caused.

[Postscript Jan. 15 2018 7:00 UTC]
All scheduled updates have been completed. Thank you for your patience.