Time capsule not showing but WIFI connection working

Unfortunately, this issue is not new and has been reported a number of time since OS X Mavericks.

The AirPort Utility relies on both the mDNS (aka, Bonjour) & the IPv6 IP protocols to find an AirPort base station.

When having difficulties accessing the AirPort thru the AirPort Utility, try the following, in order, checking for accessibility with the utility after each step:

• Check the local connection. If you are trying to access the AirPort wirelessly, make sure that you are connected to its wireless network before running the AirPort Utility to administer it. If you are still unable to access it with the utility, temporarily connect your computer directly using an Ethernet cable to one of the base station's LAN ports.
• Try accessing the base station by using the Utility's File > Configure Other… option. Then enter the LAN-side base station IP address (the default is: 10.0.1.1) and base station's administrator's password.
• Verify that both the base station and your computer are configured for IPv6 Link-local only.

  For a Mac: System Preferences > Network > Wi-Fi or Ethernet > Advanced > TCP/IP tab > Configure IPv6: Link-local only

  For the AirPort base station:
  Note: You may need to temporarily connect your Mac or PC directly to the base station by Ethernet to access it.

  • From a Mac: AirPort Utility > Select the base station > Edit > Internet tab > Internet Options… > Configure IPv6: Link-local only
• From an iOS device: AirPort Utility > Tap on the base station > Tap on Edit > Tap on Advanced > Tap on IPv6 > Change Configure IPv6 to: Link-local only > Tap on Done
• Power cycle the base station. Remove the power adapter's plug from the power outlet, and then, wait 15 seconds before plugging it back in.
• Perform a "factory default" reset on the base station.
• Finally, if you are attempting to access the AirPort via an Ethernet connection, be sure that your Ethernet port is NOT configured for Jumbo Frames, i.e., using an MTU of 9000+.

Yes, same problem here. Are you logged in with "Back to my Mac" and Apple ID on the TE and AE?

Try removing the Apple ID login and see if they reappear? Not a solution but it's something with BTMM and the AppleID authetication. A number of other threads with the same issue of late.

We are not alone! Out of the Blue both my Extreme and Time Capsule do not show anymore but they do work! I restarted the Extreme without luck. As you can see the Express is not hit. My guess is that Apple has more to do with this. Let's sit and wait.

I can access the Extreme via Configure another ... (wired)!

Are you able to access both base stations using the Configure Other... option in the AirPort Utility? If so, then this appears to be related to the mDNS IP protocol. Resolving DNS names is one of the tasks performed by mDNSResponder. It was used since OS X Jaguar, but was replaced for Yosemite with discoveryd, and subsequently mDNSResponder was brought back with El Capitan as there were numerous issues with device discovery on the local network.

Is your MacBook Pro still running OS X Mavericks? Is the MBP the only device unable to "see" the base stations in the AirPort Utility? That is, if you use AirPort Utility on an iOS device or Windows PC, do they too have the same problem? ... or another Mac running El Capitan?

All Mac's (2 x Mac, 2 Airbooks and Macbook run on El Captain). But this event happened out of the blue today on all wired and wireless devices (iPad and iPhone included). However, the network is okay, just tried to push a TM copy (wired, which failed). Is there a service from Apple that influences this or is some update silently pushed towards us?

Quote:

• Check the local connection. If you are trying to access the AirPort wirelessly, make sure that you are connected to its wireless network before running the AirPort Utility to administer it. If you are still unable to access it with the utility, temporarily connect your computer directly using an Ethernet cable to one of the base station's LAN ports.
• Try accessing the base station by using the Utility's File > Configure Other… option. Then enter the LAN-side base station IP address (the default is: 10.0.1.1) and base station's administrator's password.
• Verify that both the base station and your computer are configured for IPv6 Link-local only.

  For a Mac: System Preferences > Network > Wi-Fi or Ethernet > Advanced > TCP/IP tab > Configure IPv6: Link-local only

  For the AirPort base station:
  Note: You may need to temporarily connect your Mac or PC directly to the base station by Ethernet to access it.

  • From a Mac: AirPort Utility > Select the base station > Edit > Internet tab > Internet Options… > Configure IPv6: Link-local only
• From an iOS device: AirPort Utility > Tap on the base station > Tap on Edit > Tap on Advanced > Tap on IPv6 > Change Configure IPv6 to: Link-local only > Tap on Done
• Power cycle the base station. Remove the power adapter's plug from the power outlet, and then, wait 15 seconds before plugging it back in.

/Quote

All done, I consider disabling Back to my Mac and if that won't work downgrading the Extreme software. I can see in my log file the issue occurred on August 11, after 21:30 CET. Because my last TM-copy is from 8/11 21:41 CET.

Guess what? Disabling Back to my Mac gave me my first Extreme back! Now the TM ...

Sorted ... issue in Back to my Mac ... just disable it. I have read the pro's and decided I can live without them for now.

Worked, thanx!