Now I have Ubuntu 18.10 installed. Workaround is to use a working grub2 (for example booting up with Ubuntu 18.04 installation media) and move to grub command line. There I created a new menuentry for loading Ubuntu 18.10 installer from another USB stick.
https://askubuntu.com/questions/436519/boot-efi-files-from-grub2 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1798171 Title: System fails to boot with \EFI\BOOT\mmx64.efi - Not Found To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1798171/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
