I tried updating my Intel N5105 box to 26.7 but its hanging on boot at this point (see linked image).
https://imgur.com/oqbZz3E
https://www.reddit.com/r/opnsense/comments/1uwz7y9/comment/oxo7bx0/
I am having the same issue... System hangs on boot at "masks"
I finally got the 26.7 upgrade to install. I had to remove the "os-cpu-microcode-intel" plugin and reboot. Then I tried the upgrade again and it worked...
OK... So I tried enabling the "os-cpu-microcode-intel" plugin again after upgrading to 26.7 and it caused the system to hang on boot again in the same spot "masks"... So I would suggest that if you have this plugin installed that you remove it before attempting the upgrade and don't re-install it afterward...
@franco is there an official method to select early or late loading of the microcode updates when using the plugin?