[bitfolk] Errors from apt-get upgrade in Ubuntu 18.04

Hi All, I have just done a "sudo apt-get update" and "sudo apt-get upgrade" and got the following messages on the screen. update-initramfs: Generating /boot/initrd.img-4.15.0-54-generic update-initramfs: Generating /boot/initrd.img-4.15.0-52-generic depmod: WARNING: could not open /var/tmp/mkinitramfs_hecyM2/lib/modules/4.15.0-5 2-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_hecyM2/lib/modules/4.15.0-5 2-generic/modules.builtin: No such file or directory update-initramfs: Generating /boot/initrd.img-4.15.0-50-generic update-initramfs: Generating /boot/initrd.img-4.15.0-48-generic depmod: WARNING: could not open /var/tmp/mkinitramfs_1XbniU/lib/modules/4.15.0-4 8-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_1XbniU/lib/modules/4.15.0-4 8-generic/modules.builtin: No such file or directory update-initramfs: Generating /boot/initrd.img-4.15.0-47-generic update-initramfs: Generating /boot/initrd.img-4.15.0-46-generic depmod: WARNING: could not open /var/tmp/mkinitramfs_acPqsQ/lib/modules/4.15.0-4 6-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_acPqsQ/lib/modules/4.15.0-4 6-generic/modules.builtin: No such file or directory update-initramfs: Generating /boot/initrd.img-4.15.0-45-generic depmod: WARNING: could not open /var/tmp/mkinitramfs_bPQxlw/lib/modules/4.15.0-4 5-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_bPQxlw/lib/modules/4.15.0-4 5-generic/modules.builtin: No such file or directory update-initramfs: Generating /boot/initrd.img-4.4.0-116-generic WARNING: missing /lib/modules/4.4.0-116-generic Ensure all necessary drivers are built into the linux image! depmod: ERROR: could not open directory /lib/modules/4.4.0-116-generic: No such file or directory depmod: FATAL: could not search modules: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_B46ktb/lib/modules/4.4.0-11 6-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_B46ktb/lib/modules/4.4.0-11 6-generic/modules.builtin: No such file or directory update-initramfs: Generating /boot/initrd.img-4.4.0-112-generic WARNING: missing /lib/modules/4.4.0-112-generic Ensure all necessary drivers are built into the linux image! depmod: ERROR: could not open directory /lib/modules/4.4.0-112-generic: No such file or directory depmod: FATAL: could not search modules: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_gDoz9s/lib/modules/4.4.0-11 2-generic/modules.order: No such file or directory depmod: WARNING: could not open /var/tmp/mkinitramfs_gDoz9s/lib/modules/4.4.0-11 2-generic/modules.builtin: No such file or directory Setting up apache2 (2.4.29-1ubuntu4.8) ... Processing triggers for initramfs-tools (0.130ubuntu3.8) ... update-initramfs: Generating /boot/initrd.img-4.15.0-54-generic ian@hobsoni:~$ I am using the standard Ubunutu 18.04 LTS kernel and software. What do these warnings and errors mean? Can I safely ignore them? And if not, how can I fix? Regards Ian -- Ian Hobson Tel (+351) 910 418 473