I am a Mac User who has just downloaded Virtualbox as my VMWare appliance expired. I have followed these instructions https://manual.cs50.net/appliance/3/VirtualBox/ yet there appears to be a file error and for whatever reason I cannot open the CS50 appliance. Can someone please help me out? Thanks in advance!
Version 3 of the appliance is years old. You should be using version 2014.
As a CS50x student, you can get a "valid until end of 2015" VMWare Fusion 7 license via the CS50x Software Center as explained here:
If for some reason you want to use VirtualBox (or your Mac isn't compatible with VMWare Fusion), here are the latest instructions: