Apple released the 10.8.2 update to Mac OS X a few days ago. It breaks VirtualBox, causing the following error to come up when you try to power on your virtual machine.
VT-x is being used by another hypervisor. (VERR_VMX_IN_VMX_ROOT_MODE).
VirtualBox can’t operate in VMX root mode. Please close all other virtualization programs. (VERR_VMX_IN_VMX_ROOT_MODE).
Result Code: NS_ERROR_FAILURE (0×80004005) Component: Console Interface: IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb}
I’m on a Macbook Pro Retina, and I had the same problem. Downgrading to 10.8 fixes the issue and allows VirtualBox to run again.
To downgrade to 10.8,
- Grab a copy of the OS X 10.8 InstallESD.dmg.
- Use Disk Utility to restore to a USB drive (minimum 8gb).
- Boot from USB (Hold down Option key when booting).
- Make sure you’re disconnected from the Internet (prevents the installer from auto updating).
- Select “Reinstall Mac OS X”
Hope this helps someone out there.
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Thank you! At last, all i could find were identical problems and no solutions. Thanks for a short ‘n’ sweet straight answer.
— Karl · Oct 4, 10:31 AM · #