I finally found a solution. The problem appears to be that the firmware version I was upgrading from was too old compared to the latest one. This thread pointed me in the right direction:
https://www.snbforums.com/threads/asus-firmware-update-problems.54835/
And SOFTPEDIA had an intermediate...
Thanks for the suggestions. On Rescue Mode, I definitely got my router into rescue mode successfully (power light flashing) and was able to connect to it (ping and http).
The RT-AC56U has a rescue mode mini-web interface through which you can reset the NVRAM and upload firmware. I used this and...
I did try rescue mode, the simple web interface seemed to work but version didn’t change. The firmware restoration utility couldn’t find my router, despite my being able to access the rescue mode web interface.
I have an ASUS RT-AC56U which is currently on Firmware version 3.0.0.4.374_4561 and I am trying to upgrade it to the final firmware revision released by ASUS (382_51641) which I have successfully downloaded to my PC.
I have tried a number of methods to complete the upgrade:
1. Automatic...