Airport utility an error occurred while updating the configuration
Anyway it's working now in bridged mode, but I still want to know why it stopped working and whether I even have any other options; DHCP NAT it complains about double NAT even if I disable NAT and DHCP on the modem, DHCP only I can't figure out at the moment.
Please clarify your specific problem or add additional details to highlight exactly what you need.
In both cases, Air Port Utility will happily allow me to set up the Time Capsule and have it join my existing network.
When I go back and tell Air Port Utility to have it my wireless network, the Time Capsule tries to update itself and then just fails.
Also, be aware, the factory reset on the AEX is tricker than it seems.
For some reason I was finally able to reach it after unplugging the Airport Express that was configured to extend the network, but I wasn't able to get it configured in a way that would work with the two routers. So I did a factory reset on the Airport Extreme and now Airport Utility only shows it under "Other Wi-Fi Devices" and when I try to connect to it, "An unexpected error occurred". I'd guess that my computer was somehow expecting information it wasn't getting and I should find some way to delete all of Airport Utility's remembered data.
As it's currently written, it’s hard to tell exactly what you're asking.