- Go to Grade Administration > Single view
- Select the User
- Check the Override box
- Enter a new grade
- Click Save
After clicking save, I get a blank page. And when I refresh, no change has been made when I check the grade of the user.
It's been like this since upgrading to Moodle 3.1+ and it's still the same after upgrading to the latest Moodle 3.1.1+. No such problems though with Moodle 2.x.