VirtualBox Refusing to Launch Virtual Machines

VBAfter I upgraded to the latest version of VirtualBox, my virtual machines wouldn’t launch. The error reported did not seem very helpful — something like the following.

Unknown error creating VM (VERR_SUPLIB_WORLD_WRITABLE)

Googling around, I found an entry in the forums from February 2011 that suggested removing world-writeable permissions from the OS X main Applications folder (/Applications). I checked, and sure enough, that folder on my system was world-writeable.

Wow! That’s troubling! That folder ought not be world-writeable! So, was the VirtualBox installer responsible for making it world-writeable? I don’t know, but making that change at the command line as follows resolved the problem.

    #sudo chmod o-w /Applications

VirtualBox USB 2.0 errors

VBI was getting error messages regarding USB 2.0 when launching Windows virtual machines in VirtualBox 4.0+. The message mentioned loading the “Oracle VM VirtualBox Extension Pack”. Like Oracle’s VirtualBox, the extension pack is free.

The extension pack can be downloaded from the [VirtualBox download page]( It’s a one size fits all extension. The link is as follows.

Instructions for installing the extension pack are available [in the online manual]( I also found [abbreviated instructions]( in the VirtualBox forums.

Everything worked for me as advertised.