Avoiding Duplicate UUID Error in VirtualBox

Sometimes you may encounter a strange error saying that it failed to open hard disk because UUID of the disk already exists in the media registry. In this case, what you need to do is to change the UUID of the virtual disk file using the following command in terminal

$ vboxmanage internalcommands sethduuid /location/of/virtual/disk.vdi

This command will simply change the UUID and you can successfully add the virtual disk to your virtual machine! (tested on VirtualBox 5.0.10)

By the way, if you are using Mac OS X, the command will be
$ VBoxManage internalcommands sethduuid /location/of/virtual/disk.vdi