In Virtualbox I have recently got this error message. All hard drives and external media are mounted and I still get this message. Why?
One or more virtual hard disks, CD/DVD or floppy media are not currently accessible. As a result, you will not be able to operate virtual machines that use these media until they become accessible later.
Press Check to open the Virtual Media Manager window and see what media are inaccessible, or press Ignore to ignore this message.