1. How to regain access to Webmin with IP Access Control enabled
Edit : /etc/webmin/miniserv.conf
Add your IP to : "allow"
Example :
allow=12.34.56.78 98.76.54.32
To repair a broken grub boot from a linux live CD/DVD/USB. For the grub2 EFI boot from uEFI mode and BIOS for BIOS mode.
Then install boot-repair tool from PPA
#Add PPA
sudo add-apt-repository ppa:yannubuntu/boot-repair
#Update apt
sudo apt-get update
1. get THE UUID from blkid
Ex   /dev/mapper/encrypted-partition: UUID="d62cb037-e5ba-4f49-a92a-69705e4bae2b" TYPE="crypto_LUKS"
not   /dev/mapper/luks-d62cb037-e5ba-4f49-a92a-69705e4bae2b: UUID="f6d930b6-b75b-440c-9b41-67ed538bdd75" TYPE="ext4"