This happens after updating into the MacOS Bug sur. And then trying to start the VirtualBox VMs, Tried so far and no luck with below options,

  1. Un-installed and re-installed the VirtualBox
  2. Created completely new VM and tried
  3. Re-installed Oracle_VM_VirtualBox_Extension_Pack-6.1.16

Anyone else came a cross with the same issue? any clue to resolve this would really appreciated.

This the the complete Error message

Failed to open a session for the virtual machine New Ubuntu.

The virtual machine 'New Ubuntu' has terminated unexpectedly during startup with exit code 1 (0x1).

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: MachineWrap


  • Running brew install virtualbox from the terminal did the job for me, and “allow oracle” in “Security & Privacy” Jul 15, 2021 at 20:30

2 Answers 2


This worked for me

sudo su
csrutil clear
  • Then uninstall (from the official uninstaller) and re-install VirtualBox
  • If prompted, go to System Preferences - Privacy - General and accept the extensions
  • Reboot
  • 1
    Thank you. It worked.
    – Raju
    Jan 9, 2021 at 13:07
  • Saved my day, great thanks.
    – paky
    Feb 1, 2021 at 2:03
  • I had to do this again after updating Big Sur to 11.5. But I did not have to uninstall VirtualBox though. Thanks for this guide.
    – ond1
    Jul 23, 2021 at 8:53
  • 2
    This did not help me, unfortunately.
    – Dronir
    Sep 8, 2021 at 10:11
  • 1
    I'll add to my previous comment that I was dumb, and forgot I was on my M1 mac, where VirtualBox should not even work at all.
    – Dronir
    Sep 23, 2021 at 6:31

I received an error like this when trying to open a VM from the VirtualBox UI. (This was my first time installing VirtualBox or any VM.) I was able to run the VM from the commandline using:

VirtualBoxVM --startvm <VM ID or unique name>

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