After ubuntu14.04 was upgraded to ubuntu16.04, the installation process was interrupted and fell into a black screen. After waiting for a long time, there was no improvement.
So forced shutdown and restart, did not work, or black screen.
My solution:
Press Ctrl+Alt+F1 under the black screen to enter tty1 and execute the following command:
sudo apt-get upgrade
Prompt the following command
sudo dpkg --configure -a
It probably means: use the package management system (dpkg) of the "Debian" operating system to repair all the packages again
Wait a few minutes and restart after execution is complete
reboot
Successfully entered the desktop 16.04LTS