This applies only to Cubbli freshmen (fuxi) laptops which have Ubuntu version 20.04 installed.
Sometime after December 1st Ubuntu issued an update to sssd daemon, which stops sssd from starting up in Cubbli freshmen laptops and prevents the laptop from booting properly. This is how the problem looks like:
To fix this yourself you need to restart the laptop in recovery mode. Hit CTRL+ALT+DEL. You need to enter Grub boot menu by hitting Esc key while the screen looks like this:
Then select "Advanced options for Ubuntu" from the boot menu:
Then select "recovery mode":
You will get a menu with a few options. Select "Drop to root shell prompt". Then hit Enter to actually get to the root shell prompt. Enter the command
systemctl disable sssd at the prompt (with an L, not systemctl1):
The hit Ctrl+Alt+Del to restart the machine. It should now restart normally.