Comment 4 for bug 1574316

I'm seeing this too when I try to boot the 16.04 release images with Virtualbox on a 16.04 host system (doesn't matter which flavour, I have tested Ubuntu, Lubuntu, Ubuntu Mate so far). The arch of the host is amd64, this bug appears identically on i386 and amd64 guests.

I also can confirm that Beta 2 images are not affected. Perhaps some change to Xenial after Beta 2 release triggers a bug a Virtualbox?