Solved: VBoxGuestAdditions.iso (VERR_PDM_MEDIA_LOCKED)Solved:

Situation: 

   When inserting Guest Additions CD Image in a Debian VM you are getting VERR_PDM_MEDIA_LOCKED 

Solution: 

   There are many solutions, like: 

1) Executing 

  sudo apt-get upgrade 

  sudo apt-get install virtualbox-guest-additions-iso

2) Removing and inserting the cd from the VM configuration

and a third one which is the one that worked with me:

a) Start the VM

b) Open a terminal

c) Execute this:

  sudo su

  cd /media

  mkdir cdrom

  mount /dev/cdrom /media/cdrom

  cd cdrom

  sh VBoxLinuxAdditions.run

Hope this helps.

Alejandro,

Virtualbox in Windows. Bridge adapter + IPv6 not working

Introduction:
  When trying to use IPv6 in Virtualbox inside a guest where the adapter is bridge to the wireless interface of the host, the VM does SLAAC correctly but HTTP or ping6 does not work.

Solution:
  To solve this issue just reinstall/repair your current Virtualbox instalattion (version 5) adding the following parameters to the installer: "-Win.exe -msiparams NETWORKTYPE=NDIS5"

The result would be something like:

G:\>VirtualBox-5.0.12-104815-Win.exe -msiparams NETWORKTYPE=NDIS5

So, you cannot double click on the installer, you need to do it from command line with admin privileges.

Workaround:
  The problem is only with the bridging to the wireless adapter, you, if possible, you could bridge to a non-wireless interface and IPv6 should work perfectly.

References:
https://www.virtualbox.org/ticket/14457

Good luck,