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

Question

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}

Answer 1

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.

Answer 2

Are you using VirtualBox 4.3.14? There's a known bug which could be related: https://www.virtualbox.org/ticket/13187

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