Airport Utility in Yosemite simply doesn't see my 802.11ac Extreme (which I'm connected to via wifi) or my older Express (message at the bottom: No configured Airport base stations have been found. Airport Utility will continue searching). They used to show up perfectly fine. Now all I get is the Internet "globe" and nothing else. Airport Utility on my iPhone, though, works perfectly fine, allowing me to manage both base stations.
Do I need to "reset" AU? I've never seen this behavior before.
Steve