Exchange Server 2013, Outlook 2010/2013. The Outlook feature that allows entering an Active Directory group as an email recipient or calendar attendee recently stopped showing all groups or individuals inside it after clicking the “+” or double clicking the group name. Instead, it only shows the first entry of the next level. The distribution still works correctly, but expanding the list, for example to view everyone’s shared calendar, does not. For example, “Everybody” is comprised of “contractors” and “employees”. Expanding “Everybody” should show both groups as the next level, but only “contractors” appears. Similar behavior for groups within groups. However, everyone within the group (such as “everybody”) does receive the email, so the actual distribution is working. It’s just displaying the expansion that isn’t working correctly. This worked fine a few weeks ago - we don't know what changed.