I'm very new to both ubuntu and vbox so i apologize in advance for any things that are super obvious. im running ubuntu 16.04 ive got vbox5 running kali linux the latest version. It runs fine my issue is when i try to enable the guest whatevers so i can share a clipboard and everything else. i go to devices and click "insert guest additions cd image" and i get an error. "unable to insert the virtual optical disk /home/peter/.config/VirtualBox/VBoxGuestAdditions_5.0.40.iso into the machine, would you like ti try to force the insertion. I have searched for a fix for about two hours and have found nothing so any help would be appreciated.