I had the same issue with the following setup: EXT4+ GRUB + LUKS After some back and forth, i was successful with a way that Grok helped me with: “Forcing LUKS1” As soon as you are in CachyOS live ISO, open the terminal and: 2) sudo nano /etc/calamares/modules/partition.conf Replace every luks2 with luks1 (should be 3-4) ; save & exit. Start Calamares - pick “Erase disk”, set a password for Encryption, Bootloader GRUB Complete the installation and boot into the system. There is also a way to chroot into your system after a regular install and encrypt it.