In the - unlikely - case, that there should be a problem, going back to the snapshot point (in the VB Manager after powering down the VM) means, that the VM is exactly at the same state as before (inclusive the old guest additions of course). p=1164290#p1164290 , I decided to uninstall the VB software that I installed from the Package Manager, so I clicked Menu, All Application, Oracle Virtual Box, RMK (Right Mouse Key), Uninstall. Then I went to Oracle's site and downloaded the version for Ubuntu 14, 64 bit. Now I was in trouble because I could no longer start Package Manager.
Only caveat: In case, that you did not shut down your guest, but used the save state function for quitting, you should at first start the VM and shut it properly down. Today I wanted to add a second guest OS, being Win7 64 bit.
Mike, you are right, that your machines do not get affected by the updates - just as your office documents do not get affected by updating Libre Office. But if all works well in your current version, I'd simply disable the "new version" notification in the preferences and stick to what you've got.Updating VB is cumbersome, because it entails updating the Extension Pack and the Windows Guest Additions in your Windows VM as well, which doesn't always go smoothly.Doing so essentially broke the device as the updated version of Ubuntu downloaded was not designed for the Jetson TX1 architecture.The Jetson TX1 requires a special version of Ubuntu which can be installed through a program called Jetpack.