package:grub-efi-amd64-signed:1.187.6~20.04.1+2.06-2ubuntu14.4
Setting up grub-efi-amd64-signed (1.187.6~20.04.1+2.06-2ubuntu14.4) ...
The disk contains an unclean file system (0, 0).
Metadata kept in Windows cache, refused to mount.
Falling back to read-only mount because the NTFS partition is in an
unsafe state. Please resume and shutdown Windows fully (no hibernation
or fast restarting.)
Could not mount read-write, trying read-only
Installing grub to /var/lib/grub/esp.
Installing for x86_64-efi platform.
grub-install: error: /var/lib/grub/esp doesn't look like an EFI partition.
Installing grub to /boot/efi.
Installing for x86_64-efi platform.
Installation finished. No error reported.
dpkg: error processing package grub-efi-amd64-signed (--configure):
 installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1