efi system partition (esp) not usable your efi system partition (esp) is not mounted at /boot/efi. please ensure that it is properly configured and try again.
efi system partition (esp) not usable your efi system partition (esp) is not mounted at /boot/efi.
solve 100%
https://askubuntu.com/questions/1008974/cannot-update-to-18-04-on-dualboot-efi-system-partition-esp-not-usable
1.you have to add a line to your sudo nano/etc/fstab
#note can you find UUID from Disks app in ubuntu ##
UUID=XXXX-XXXX /boot/efi vfat umask=0077 0 1
2.and add in terminal
sudo mount /boot/efi