Answer to: After upgrading to 7.4.2 Air Disc won't connect anymore.There seems to be a lot of issues with 7.4.2 version firmware for the Airport Extreme. Mine would lose connection to the disks regularly, and I'd have to restart the basestation (switch off or restart via Airport Utility) to get the connection back. I tried many things to resolve this, but nothing worked and in the end I rolled-back to 7.4.1 and everything is fine now, and has been for several months - much more reliable connection to disks attached to the basestation. So that's what I'd recommend. The only issue is that Airport Utility sometimes warns me that a 'basestation is reporting issues" - that is just the basestation seeing there's a firmware upgrade available. Just ignore it. This isn't really a fix, but it seems the only workaround I can find. Hope it helps.