Steps to reproduce:
- Create a course.
- Enrol 1 user as students.
- Create an assignment and, in "Grade -> Grade", set "Type" to "point" and "Maximum grade" to 10.
- Save changes.
- Go to the course grades, click over the "Turn editing on" button (to enable quick grading).
- Set grade for student 1 to 50
- Check the grade is set to 10 (instead of 50), because it's the maximum allowed.
- Turn editing off
- Access to the "Single view" tab and select the assignment.
- Mark the "Override" column as checked, set the grade for student 1 to 50 and save.
- Check the grade is not saved.
The expected behaviour should be consistent in both scenarios (when saving a grade from the Grader report and when overriding from Single view).