Virtual Box conflicting guest additions ("Got different reports about installed GuestAdditions version") - Ubuntu 16.04

downgrade-vbox-guest-additions.md

Downgrade Virtualbox guest additions in your virtual machine (Ubuntu 16.04)

Make sure your VM is running and ssh into it. From there, run the contents of downgrade-vbox-guest-additions.sh below.

Stop vagrant-vbguest automatic updates

From your host machine, if you have the vagrant-vbguest plugin installed, make sure you deactivate it for this specific VM. To do that, set auto_update to false in your Vagrantfile:

config.vbguest.auto_update = false

Reload Vagrant

vagrant reload

Re-enable vagrant-vbguest automatic updates

As soon as things have been fixed (on Oracle's side...) and the latest guest additions work again, re-enable auto-updates by removing the line you added in step 2 and run

vagrant vbguest --do rebuild

downgrade-vbox-guest-additions.sh

# Downgrade VBoxGuestAdditions. [This example will work for Ubuntu 16.04+ only, but it can be easily changed to work on other versions and distros as well]
# Run this script from your virtual machine (guest)

# See list of versions here: http://download.virtualbox.org/virtualbox/
GAV=5.0.26

sudo apt -y autoremove
sudo apt -y update
sudo apt -y install \
    linux-generic \
    linux-headers-$(uname -r)

wget http://download.virtualbox.org/virtualbox/${GAV}/VBoxGuestAdditions_${GAV}.iso -O VBoxGuestAdditions.iso

sudo mkdir /tmp/vbox
sudo mount -t iso9660 -o loop -r VBoxGuestAdditions.iso /tmp/vbox
sudo sh /tmp/vbox/VBoxLinuxAdditions.run

sudo umount /tmp/vbox
sudo rm -rf /tmp/vbox
sudo rm VBoxGuestAdditions.iso

You've saved me a lot of trouble, thank you for sharing this.

Glad it could be of help :)