I have a Mac mini running the latest version of Mavericks. For my network, I have a 2011 Airport Extreme connected via Ethernet to my ISP's wireless router and configured as a bridge router. Because the wireless signal was weak at the other end of the house, I bought an Airport Express in 2012 to extend the network. All was fine until last year, when the Airport Express started randomly disconnecting, with the light flashing amber. Cycling the power off and on temporarily fixed the problem. Last December, I updated the firmware in both devices to 7.6.4. I tried doing a full reset on the Airport Express. Last month, I changed ISPs (from Comcast to Frontier) for price reasons. The problem persisted. Eventually, it got so bad that I figured my Airport Express had become faulty because I had it near a hot A/V receiver for too long. Yesterday, I bought a new Airport Express. It took me half a dozen attempts to configure it and get past the "An unexpected error occurred. Please try again." error message, but I finally got it set up. Well, the new one has the same problem as the old one. Curious, I hooked the old one back up. It turns out that they both lose connection at the same time. When I cycle the power off and on, they'll remain connected to the network from a few seconds to a few minutes to half an hour, with the lights green. Then they'll both randomly go to flashing amber. The Airport Extreme never goes off line -- or, if it does, it reconnects automatically, and I don't know that it was down. Airport Utility accurately reflects the status of all three devices. Any ideas? Since I've tried two Airport Expresses, two ISPs, and two primary routers (supplied by the ISPs), the problem has to lie with either the Airport Extreme or Mavericks. It occurs to me that I can try removing the Airport Extreme from the equation, and configuring one Airport Express as a base station and the other as a network extender.