We'll be releasing some new highly requested improvements to the Access Control functionality tomorrow which is going to require the panel to be unavailable for about 30 minutes or so. Panel downtime is unfortunately unavoidable due to the fact that access control is a deeply-ingrained part of the system. To be clear, servers will remain online but you won't be able to access the panel during this time.
The update is intended to allow users to better refine the access people have to their server panel via the use of customisable roles. The user can define roles with access to specific resources and then apply those roles to specific users. Here are a couple of pictures to demonstrate this:


You'll get the 4 default roles applied to your account after this update is rolled out and you'll then be free to configure them however you'd like.
I'll be posting closer to the maintenance window but I expect the downtime to occur around 13:00 EDT (18:00 UTC) on the 9th of September.