That's very weird. I just try to re-download the image. I then imported it in vBox and configured it as Linux. I then booted it and was able to get to the login screen.
Step 1 - Imported in vBox
Step 2 - Selected Linux as machine type
Step 3 - Got to the login prompt
I am using a Mac OS X version 10.11 with vBox version 5.0.14