by Philippe Decloitre.
Hello Emma
Thank you for taking the time to answer
Unfortunately the problem seems deeper:
Ever since we moved the location of our Moodle a number of actions are not possible anymore:
Backup, Restore, Grades open blank pages (an absolutely white page, no error message)!
When I tried to upgrade some plugins I obtained "absent from disk" errors.
The weird thing is that most pedagogical activities are fully fonctionnal (I use mostly my Moodle for students to practice with HP (hot potatotes) activities).
There are a large number of these and they are chained (takes quite some work to create)
This is why I would like to salvage what I did on the 2.9; even though it's lost it backup function.