Apple has released AirPort Utility 6.3.1 (http://support.apple.com/kb/DL1664) for Mac OS X 10.7.5 or later.
You use AirPort Utility to set up and manage your 802.11n and 802.11ac AirPort base stations, including AirPort Express, AirPort Extreme, and AirPort Time Capsule. AirPort Utility 6.3.1 resolves an issue where AirPort base stations may not appear in AirPort Utility.