When you run the VM VirtualBox should pop up a window that will show console output. If there were errors encountered 
when booting the VM, they will hopefully appear there.

If this was the first time you've used VirtualBox and you haven't already done so, you will have to configure a network 
for it (for whatever reason it doesn't have one by default). This is described in the documentation for mkqnximage (the 
tool Momentics uses to build and run VMs).