User Switching, Multiple user accounts not working

dewet

How to add a different user and log in as that user?

Getting random black screen boots, TV screen turning on/off if I try to log-in as another user.

Can only use Firefly user that automatically logs in.

busybee

Please try this in the Ubuntu system:

sudo mkdir /var/lib/lightdm

sudo chown lightdm:lightdm /var/lib/lightdm