upgrading from latest firmware to latestr asuswrt-merlin fails

[Andrus]

RT-AC87U was upgraded to latest asus firmaware.

I tried to upload latest Asuswrt-Merlin from Windows 10 to it but got error

Firmware upgrade unsuccessful. This may result from incorrect image or error transmission. Please check the version of firmware and try again.

I re-booted router, tried with Chrome, IE and Edge.
USB ports in router are empty.
Problem persists.

How to upgrade to AsusWrt-Merlin ?

 

[AndreiV]

http://www.snbforums.com/threads/as...-verification-method.32357/page-6#post-262504

http://www.snbforums.com/threads/im...le-with-asus-3-0-0-4-380_3000-or-newer.32962/


Look before you leap.