1. VirtualBox common issues
    1. Extension pack
    2. Missing VM
    3. VM copying
      1. Case
      2. Solution
    4. VM failed to start
      1. Case
      2. Solution
    5. QT FATAL
      1. Case
      2. Solution
      1. Case
      2. Solution
    7. Other notes related with VirtualBox
      1. DKMS
      2. Groups
      3. UUID
      4. Help about VirtualBox

Author: Edmund Laugasson

VirtualBox common issues

Following commands are tested in Ubuntu Linux and/or Linux Mint 64-bit LTS-version.

Extension pack

what is installed:

sudo vboxmanage list extpacks

Install new extension pack and replace old one:

sudo vboxmanage extpack install --replace /path/Oracle_VM_VirtualBox_Extension_Pack-x.x.x-xxxxxx.vbox-extpack


remove old extension pack:

sudo vboxmanage extpack uninstall "Oracle VM VirtualBox Extension Pack"

clean up

sudo vboxmanage extpack cleanup

install new one:

sudo vboxmanage extpack install /path/Oracle_VM_VirtualBox_Extension_Pack-x.x.x-xxxxxx.vbox-extpack

More information in extension pack section at VirtualBox manual.

Missing VM

Sometimes it might happen that VM is missing. One possible bug exist.

One reason might be missing .vbox file located at

~/VirtualBox VMs/Example VM/Example VM.vbox

In the same folder there is usually also the file

~/VirtualBox VMs/Example VM/Example VM.vbox-prev

One workaround would to close VirtualBox and then just copy the .vbox-prev file into same location with .vbox extension:

cd ~/VirtualBox VMs/Example VM/
cp "Example VM.vbox-prev" "Example VM.vbox"
... and reopen VirtualBox.
If still the VM did not appear into VirtualBox VMs list then there is possible to add the VM back via Machine->Add menu or CTRL+A shortcut key by browsing the .vbox file and adding it.

Yet another way, when there is no .vbox* files left - create a new VM using old .vdi virtual disk image file. If there is no .vdi file then the VM is gone. It would be useful to have copy of VM either just the folder or exported into .ova - ask lecturer whether she/he has preinstalled VM as .ova somewhere.

VM copying


Copying VM folder to another storage and trying to add the machine (Machine->Add or CTRL+A) returns:

Cannot register the hard disk '/path/to/VMs/<VM name>/<VDI name>.vdi' {a73ccd48-a9b8-4274-954a-308c40634cae} because a hard disk '/path/to/VMs/<VM name>/<VDI name>.vdi' with UUID {1690f3e8-dc15-42ff-975b-4c9fa1c0b448} already exists.

Result Code:
IVirtualBox {0169423f-46b4-cde9-91af-1e9d5b6cd945}


Run at command line (replace with appropriate information about path and filename):

VBoxManage internalcommands sethduuid "/path/to/VMs/<VM name>/<VDI name>.vdi"

Open the file /path/to/VMs/<VM name>/<VM name>.vbox and correct following things (in bold):
lines 11-14:
        <HardDisk uuid="{a73ccd48-a9b8-4274-954a-308c40634cae}" location="
/path/to/VMs/<VM name>/<VDI name>.vdi" format="VDI" type="Normal"/>
        <HardDisk uuid="{a73ccd48-a9b8-4274-954a-308c40634cae}" location="
/path/to/VMs/<VM name>/<VDI name>.vdi" format="VDI" type="Normal"/>

lines 195...197:
        <AttachedDevice nonrotational="true" type="HardDisk" hotpluggable="false" port="0" device="0">
          <Image uuid="{a73ccd48-a9b8-4274-954a-308c40634cae}"/>

For more information, please look in command line:
VBoxManage internalcommands

More information:

VM failed to start


Installing new kernel, etc and at some reason new kernel modules are not compiled. Sometimes a new GCC version installation might be needed in case of very new version of kernel and old GNU/Linux distribution.


Make sure beforehand that dkms package is installed (see other notes at the below).

sudo vboxconfig

vboxconfig located at /sbin/ folder and access might be limited for regular users who have not it in path (to check: env | grep PATH)

Workaround (if previous do not work):

sudo /usr/lib/virtualbox/vboxdrv.sh setup
Restarting VB kernel modules:
sudo rcvboxdrv restart

Check whether kernel modules are loaded:
sudo rcvboxdrv status



Qt FATAL: This application failed to start because it could not find or load the Qt platform plugin "xcb". It usually happens on 32-bit platforms.


ldd /usr/lib/virtualbox/plugins/platforms/libqxcb.so | grep not
    libQt5XcbQpaVBox.so.5 => not found
    libQt5DBusVBox.so.5 => not found
    libQt5GuiVBox.so.5 => not found
    libQt5CoreVBox.so.5 => not found

sudo updatedb
locate libQt5XcbQpaVBox.so.5


sudo ln -s /usr/lib/virtualbox/libQt5XcbQpaVBox.so.5  /lib/i386-linux-gnu/
sudo ln -s /usr/lib/virtualbox/libQt5DBusVBox.so.5  /lib/i386-linux-gnu/
sudo ln -s /usr/lib/virtualbox/libQt5GuiVBox.so.5  /lib/i386-linux-gnu/
sudo ln -s /usr/lib/virtualbox/libQt5CoreVBox.so.5  /lib/i386-linux-gnu/

ls -l /lib/i386-linux-gnu/ | grep Qt



Hardware virtualization (VT-x/AMD-V) in exact virtual machine is not set.


Change either graphically from settings:

or run the command in terminal:
VBoxManage modifyvm <uuid|vmname> [--hwvirtex on|off]
e.g. VBoxManage modifyvm 171efacc-1d43-ab9d295ce-1f84e64f492a --hwvirtex on

For more information about using VBoxManage, please see here.

Other notes related with VirtualBox


DKMS - Dynamic Kernel Module Support

Please make sure that the package dkms is installed before you use VirtualBox.

In Ubuntu:

sudo apt-get update && sudo apt-get -y install dkms && sudo ldconfig && sudo dpkg --configure -a && sudo apt-get clean


When installing VirtualBox (VB), make sure that the user, who needs to use VB, are added to groups vboxusers, vboxsf. The last one is needed to share folders between host and guest in UNIX-like systems.


Overview (including UUID) of existing hard disk drives:

VBoxManage list hdds

VBoxManage showhdinfo <path>/<name>.vdi

Overview (including UUID) of existing virtual machines:

VBoxManage list vms

Filter with search string "ubuntu" (if you have used such name in virtual machine names, it is also case sensitive):
VBoxManage list vms | grep ubuntu

Help about VirtualBox

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If you find something to add, improve, etc - please let me know.