I already tried: closing all processes of VirtualBox via KSysGuard and then running: sudo apt-get remove virtualbox-5.1, sudo apt-get install virtualbox-5.1, sudo apt-get purge virtualbox-5.1, sudo apt-get install virtualbox-5.1, sudo vboxconfig, virtualbox. And then adding the extension in the VirtualBox preferences.

This does not get it installed nor does following the command-line instructions for installing it here.

Instead I only get VBoxSVC consuming 25% of my CPU. I get the following error when closing VirtualBox after trying that:

Failed to open the Extension Pack ../Oracle_VM_VirtualBox_Extension_Pack-5.1.26-117224.vbox-extpack.
Callee RC: NS_ERROR_ABORT (0x80004004)


Qt WARNING: QWidgetWindow(0x55f9acf151f0, name="UIGlobalSettingsExtensionWindow") must be a top level window.
Qt WARNING: No node found for item that was just removed: QUrl("file:///home/user/Downloads/hqdefault.jpg")
Qt WARNING: QWidgetWindow(0x55f9ace32ef0, name="UIGlobalSettingsExtensionWindow") must be a top level window.

when doing it via the command-line.

/var/log/syslog earlier had (besides some martian packets):

kernel: SUP_IOCTL_COOKIE: Version mismatch. Requested: 0x2a0000 Min: 0x2a0000 Current: 0x240000

and (var/log/kern.log) has:

kernel: VBoxNetFlt: Successfully started.
kernel: VBoxNetAdp: Successfully started.
kernel: VBoxPciLinuxInit
kernel: vboxpci: IOMMU not found (not registered)

I already this problem earlier but got it working. These problems don't look normal.

Why can't I install the Extension Pack and how can I get it working?

  • Have you installed a new kernel after your last boot? Sep 6, 2017 at 22:54
  • No. At least not deliberately. But I installed and uninstalled a driver once but not in the last couple days. What's a good way to check?
    – mYnDstrEAm
    Sep 6, 2017 at 23:01
  • Download the extensions pack from the virtualbox.org system, and login to the root user, I believe all you have to do is to open the extensions pack.
    – mdpc
    Sep 6, 2017 at 23:25
  • HaukeLaging That was the reason for why I had to reinstall VirtualBox actually. @mdpc I have sudoers rights. I won't run GUI programs like VirtualBox as root which is good practice. The vbox-extpack file is owned by my user. I know I have to open it which doesn't help if that doesn't work.
    – mYnDstrEAm
    Sep 7, 2017 at 7:20

1 Answer 1


The solution was: I had to give execute permissions for the owner to the .vbox-extpack file. For some reason it had execution rights unchecked. (I also had this problem when downloading the file via wget instead of via the browser.)

I then had to do this to get VMs working again. Until then I got this error (which is also the reason I reinstalled VirtualBox):

RTR3InitEx failed with rc=-1912 (rc=-1912)

The VirtualBox kernel modules do not match this version of VirtualBox. The installation of VirtualBox was apparently not successful. Executing


may correct this. Make sure that you do not mix the OSE version and the PUEL version of VirtualBox.

where: supR3HardenedMainInitRuntime what: 4 VERR_VM_DRIVER_VERSION_MISMATCH (-1912) - The installed support driver doesn't match the version of the user.

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