Since Juno release I am unable to boot the system with Multisystem USB (combination of GRUB and live system ISO). The boot process gets interrupted with
initramfs unable to find a medium containing a live file system.
Tried to copy the /casper directory from ISO to USB root as suggested in another answer, but the squash.fs filesystem could not be mounted.
This did not happen with Loki release.
Is there any particular change in the ISO media creation, that prevents creating and booting the Multisystem USB?