I just got done getting my settings restored to my router after letting it try to update to the latest version. Version 18.104.22.168.378.4585 killed the web interface, making it unconfigurable. Restoring the previous version from a TFTP client running on Linux wouldn’t work to set it right, either. Good thing I had recently added Windows 7 to the empty space on my main computer’s SSD, as a Windows-based unfsck-my-router utility provided by Asus (only downloaded after I had swapped in my trusty old WRT54GL temporarily) was the only thing that would get the router running right again.
I even tried using the aforementioned unfsck-my-router utility to try installing the newer firmware, instead of letting the router update itself again. That didn’t work either. The only conclusion I can come to is that something is pretty badly broken in this latest release. It won’t damage your router (it’s harder to brick than most devices), but rolling it back to working firmware is a bit of a hassle. I’d recommend skipping this update and hold off for the next release.