VirtualBox error when trying to run Ubuntu "Failed to open a session"


Im trying to run Ubuntu in a virtual machine on virtual box. So far I have reinstalled virtualbox once to see if it was the cause, then I redownloaded the .iso, but when I try to run the machine it says it still won't run.

Failed to open a session for the virtual machine ubuntu.

The virtual machine 'ubuntu' has terminated unexpectedly during startup with exit code 1.

Result Code: E_FAIL (0x80004005) Component: Machine Interface: IMachine {480cf695-2d8d-4256-9c7c-cce4184fa048}

asked on Stack Overflow Jul 29, 2014 by user3234022

5 Answers


If you didn't power off the vm after last run, try right-click on VirtualBox Manager >> Discard Saved State. This will start the vm from (virtual) power off state. Current state of vm will be lost.

answered on Stack Overflow Dec 3, 2015 by Dejan

Are you using VirtualBox 4.3.14? There's a known bug which could be related:

I was having this problem, downgrading "solved" it.

answered on Stack Overflow Aug 19, 2014 by Luiza Utsch

For me "Detachable Start" works, can you try it out?

answered on Stack Overflow Aug 12, 2016 by Anand

Here's what I did and it worked properly:

(1) Move/copy your hard disk image (my_old_vm.vdi) to a convenient folder, e.g. C:\my\VMS\my_new_vm\

(2) Create a new virtual machine (click the new button).

(2.b) At some point in time you are asked about the disk to be used; choose 'existing disk image' and browse to where you moved my_old_vm.vdi and select that.

(3) Start the VM and reconfigure the machine settings.

(4) Possibly delete the old machine. If you did not move the .vdi file, then do not delete all files related to the old machine.

This saved my day.


I just went through exactly the same problem on a Windows VM. Uninstalling the Norton Internet Security and restarting my computer solved the problem. Credit to this article that I found here:

answered on Stack Overflow Aug 17, 2014 by user3267567 • edited Oct 30, 2014 by user3267567

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