peter@ubuntu-s:~$ # Guest Additions 5.2.6 are inserted in CDrom <<<<<<<<<<<<<---------- Started with Guest Additions 5.2.6 peter@ubuntu-s:~$ sudo mount /dev/cdrom /mnt mount: /mnt: WARNING: device write-protected, mounted read-only. peter@ubuntu-s:~$ sudo /mnt/VBoxLinuxAdditions.run sudo: unable to execute /mnt/VBoxLinuxAdditions.run: Input/output error peter@ubuntu-s:~$ # As you can see, no log files have been produced peter@ubuntu-s:~$ ls /var/log alternatives.log apt auth.log bootstrap.log btmp dist-upgrade dpkg.log faillog installer kern.log lastlog lxd syslog unattended-upgrades wtmp peter@ubuntu-s:~$ sudo umount /dev/cdrom /mnt umount: /mnt: not mounted. peter@ubuntu-s:~$ # VBoxGuestAdditions_5.2.7-120528.iso inserted <<<<<<<<<<<<<---------- Changed to Guest Additions 5.2.7 peter@ubuntu-s:~$ sudo mount /dev/cdrom /mnt mount: /mnt: WARNING: device write-protected, mounted read-only. peter@ubuntu-s:~$ sudo /mnt/VBoxLinuxAdditions.run Verifying archive integrity... All good. Uncompressing VirtualBox 5.2.7 Guest Additions for Linux........ VirtualBox Guest Additions installer Copying additional installer modules ... Installing additional modules ... VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel modules. VirtualBox Guest Additions: Running kernel modules will not be replaced until the system is restarted VirtualBox Guest Additions: Starting. VirtualBox Guest Additions: modprobe vboxsf failed peter@ubuntu-s:~$ # ^^^^^^^^^^^^^^^^^^^^^^ peter@ubuntu-s:~$ ls -al /var/log/vboxadd-* -rw-r--r-- 1 root root 251 Feb 13 15:18 /var/log/vboxadd-install.log -rw-r--r-- 1 root root 255492 Feb 13 15:18 /var/log/vboxadd-setup.log peter@ubuntu-s:~$ <<<<<<<<<<<<<<<<<< REBOOT >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> peter@ubuntu-s:~$ sudo mount /dev/cdrom /mnt mount: /mnt: WARNING: device write-protected, mounted read-only. peter@ubuntu-s:~$ sudo /mnt/VBoxLinuxAdditions.run Verifying archive integrity... All good. Uncompressing VirtualBox 5.2.7 Guest Additions for Linux........ VirtualBox Guest Additions installer Removing installed version 5.2.7 of VirtualBox Guest Additions... Copying additional installer modules ... Installing additional modules ... VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel modules. VirtualBox Guest Additions: Running kernel modules will not be replaced until the system is restarted VirtualBox Guest Additions: Starting. peter@ubuntu-s:~$ # ^^^^^^^^^^^^^^^^ <<<<<<<<<<<<< NO modprobe failed message this time