I have Ubuntu 16.04 LTS, the X interface (the same as ubuntu-desktop) is not working. I managed to get to terminal mode and do apt-get upgrade and apt get dist-upgrade to see if this should solve the problem. After that the same problem with the x interface persists. It does not allow me to do anything with the computer. Except that I can open Terminal by rightclicking the mouse. I have tried to solve the problem by reinstalling the desktop 'sudo apt --reinstall ubuntu-desktop' but it does not solve the problem.
To boot into single user mode you edit the boot instructions for the GRUB menu.
- Hold down the left Shift key while rebooting to bring up GRUB menu.
- Select (highlight) the GRUB boot menu entry you wish to use.
- Press e to edit the GRUB boot commands for the selected boot menu entry.
- Add the word "single" to the back of the line.
The problem seems to be without a solution so I upgraded to 18.04. Which solved the problem but created a new problem with WiFi access.