My extender has been down all morning stuck at step 11.C. I had to follow the threads in here to find out what that means - that it's attempting to download an update ("configuration update is in progress"), but it just fails. A factory reset made no difference, nor did a hard reboot.
Reading some of the other threads here, I'm not sure if the device is bricked, or if it will just mysteriously start working again as suddenly as it stopped.
The software version on the admin page is listed as 2.0.0.01