You might have been hit by https://bugs.launchpad.net/bugs/1679435
Could you please try to update via the command-line tool:
sudo apt update sudo apt -f install sudo apt upgrade
You might have been hit by https:/ /bugs.launchpad .net/bugs/ 1679435
Could you please try to update via the command-line tool:
sudo apt update
sudo apt -f install
sudo apt upgrade