virtualbox.org

A few days ago I updated & upgraded software on my Linux Mint 17.3 PC. It took awhile but as soon as I upgrade VB from 5.0.2 (standard install) to anything greater than that, the next reboot/restart I get ERROR'S on boot up
"Could not start X Server (your GUI)"
X Server Not found
Please install X Server or Correct MDM configurations and restart MDM.

I do not get a GUI login Screen, just dropped to tty1.

I Have noticed that when I do the install (newer version) the installer tells me it will change the following items the first being XServer.

From what Dumb-NooB I understand is that I have a standard 17.3 Mint 64bit installer ISO, and just a few programs added via built in software tools, and the usually updates & upgrades. I believe that I use an MDM GUI login, so I don't have a clue where this X Server or Xorg.conf or X11 stuff is coming from.

I have looked through the forum and haven't found anything recent regard this, but an Internet search revealed that XServer was added for XDME support of something similar.

Any suggestions even if not VirtualBox related would be helpful.
Thanks
Fred.
PS maybe relevant - I have also had problems with Firefox V46 and above looking like crap and was told I need GTK3 or above which from what I can tell is already installed. How to get my computer to use GTK3 is still a mystery.

So everything you have posted seems to be host OS related, even the VBox upgrade I am afraid. When you say upgrade, do you mean upgraded packages or distro versions, and was the original version of VirtualBox from the distro or virtualbox.org?

The built in distro version of Virtualbox is 5.0.? . I have manually downloaded 5.0.2 and installed that version (I think there is a USB problem). If I download and manually install 5.0.4 or above I get a warning box that reads "the following items will be changed" and xserver is the first one.

As for the Linux mint 17.3, I have done update, upgrade and dist-upgrade, before attempting manual update of Virtualbox.

Does this help?

Should I remove Virtualbox and just install what the distro package manager will install ?

Thanks

I am still at a loss to understand exactly what is happening. The install of VirtualBox does not change the OSes xserver. As a suggestion I would purge the install and download the official version from virtualbox.org as well as the extension pack and try a fresh install.