The command /groster /guildroster has stopped working since season two has started.
This enabled anyone to sort through the roster by time character had last logged on, making it so much easier to keep track of active members, and remove inactive members if needed.
You could also sort by activity/rank/note etc making it easier to find a member and all their alts in the roster together.
I assume this is a bug, as you would not remove such an important guild function when there is no other way to do this. The new guild UI does not have ANY of this functionality.
All other guild / commands still work from the old system (/ginfo /gremove /gpromote etc), just not /groster.