Booting from FAT seems to be broken in 8.00

Following to this guide - https://wiki.archlinux.org/index.php/systemd-boot#Grml_on_ESP installing SystemRescue on FAT partition worked fine till 8.00. The errors that appears while mounting FAT partition: FAT-fs (sdb1): IO charset ascii not found mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sdxx, missing codepage or helper program, or other error.