When I installed Lubuntu 18.04 alongside 16.04 and 14.04 it went OK apart from installing grub at the end. When switching on, I chose an entry from the hardware's boot device menu and it didn't work. I then chose the EFI entry and it worked OK.
But installing applications fails in shim-signed (/usr/lib/grub/i386-pc/modinfo.sh doesn't exist) and grub-efi-amd64-signed (cannot find EFI directory)
The applications launch and working OK, but scripts that include installing are thrown by the errors. I don't think I have an EFI process (?) or a need for one.
How can I unscramble this without starting from scratch ?
The command
seems to fix it.