We have implemented automatic closure of notebooks after 30 minutes of inactivity. You just need to click on 'Try Restarting Now' / 'Essayer de redémarrer maintenant' and run the cells from the beginning of the notebook.
⚠️ It is strongly recommended not to leave your session open and inactive for a long period.
⚠️ Log out when you have finished your exercises and exams to avoid the aforementioned issues.