- You can get to a text terminal using alt-ctrl-F1.
- Check the LightDM logs in /var/log/lightdm.
- Stop LightDM with sudo stop lightdm.
- You can try LightDM again with sudo start lightdm.
- If you have another display manager you want to try (e.g. gdm) start that: sudo start gdm.
- You can set the default display manager by running sudo dpkg-reconfigure lightdm.
- Check your system is up to date, especially video drivers.
- File a bug. If you're not sure where the cause is (lightdm / unity-greeter / unity / X / kernel) file against lightdm and the bug will be triaged and reassigned.
Tuesday, November 13, 2018
How to fix desktop problem on Ubuntu
Many things can go wrong in a graphics stack. If you can't see any graphics or see corrupt graphics the following might help: