My update from GUI failed due to a mounting error. Messages log:
Dec 10 13:55:28 freenas /updated.py: [freenasOS.Update:105] umount: unmount of /boot/grub failed: Device busy
Dec 10 13:55:28 freenas /updated.py: [freenasOS.Update:1377] Unable to mount boot-environment 11.2-RELEASE
Dec 10 13:55:33 freenas uwsgi: [middleware.exceptions:36] [MiddlewareError: Unable to mount boot-environment 11.2-RELEASE]
https://i.imgur.com/aCJK46n.jpg
Will try to reboot and see if that helps before updating
EDIT;
After reboot i tried to update again and it worked perfectly!
I dont know if this matters at all but on the first attempt i clicked the "Check Now" button and it said when updating "installing packages 1/2" and this time i used the "Apply pending updates" instead and it just said installing packages 1/1 and worked.. so not sure if the button had anything to do with it or if the reboot worked but its working flawlessly :)