I recently bought four Netgear WAC104 devices, and am flashing OpenWRT onto them. I have struggled a lot to get the firmware on, due to the not great interface they provide.
The issue is, that it prompts you to change the password, but then when you change it on the page you land on, nothing connects anymore and you can't access the router.
The solution is to click "Set Password" in the Administration menu on the left, and set it there. Even though there is a prompt to set the password on every page, that will change other settings too and break things.
The router isn't great, and the software is awful so thats why I'm installing OpenWRT anyway.
Two down, two more to go!