I'm struggling to get my Time Capsule to work. I've done a hard reset and set it up again, but then get this error:
The settings for this AirPort wireless device have been successfully updated, but there was a problem re-joining the wireless network or finding the AirPort wireless device. You may need to select your network from the Wi-Fi menu and try again.
My Wireless network is working perfectly and all other devices are connected with no issue.
Are you using another Apple router? If not, wirelessly extending won't work. You have to use an Ethernet cable (or the unsupported join functionality). I would recommend Ethernet, if you can't run a cable use Powerline adapters.