Until this morning, I was able to go to Grader report, turn on editing, and, for any student and any gradable assignment/quiz/forum item (as well as category totals and course total), enter or edit both grades and feedback by placing my cursor in the rectangular dialogue boxes (see, e.g., "Week 10 Quiz" column below). As of this morning, I am able to do so for only some items/categories (alas, the ones that I have already finished grading). For the two items I'm in the process of grading (e.g., "Research Memo"), no rectangular boxes appear anymore. If I had previously entered a grade, that grade appears, but is not editable. If I had previously entered feedback, that feedback is no longer displayed. If I hadn't yet entered a grade, the cell is empty for those students (except for the eye and lock icons--all cells are unlocked, however).
In the troublesome columns (e.g., "Research Memo"), when I click on the pencil icon (Single view for category total), I'm told "This grade item cannot be overridden."
After looking at Moodle docs for something relevant to that message, I found the following (here, under Hiding settings globally: https://docs.moodle.org/28/en/Grader_report):
Site administration>Grades>Grade category settings: 'Allow category grades to be manually overridden'. If this setting is disabled, users cannot override category grades.
I tried going to Grade Administration>Setup>Course grade settings to see if the
box marked "Allow category grades to be manually overridden" was checked or not, but received the following error:
Coding error detected, it must be fixed by a programmer: Invalid $CFG->grade_minmaxtouse value.
The other change I've noticed as of this morning, if it helps, is that the entire interface of Grader report appears larger on my screen (the rest of Moodle appears as it always has, as do other tabs in my browser). So perhaps IT at my institution upgraded Moodle overnight or something. (I've contacted him but haven't heard back and my department director doesn't know anything about any update.) I think I'm currently in Moodle 2.8 (because when I click on the "Moodle docs for this page" link at the bottom of any page, it takes me to a 2.8 document). Finally, "Grading history" appears to be an entirely new category (I see that it was introduced in 2.8), although it might have been there previously and I just never noticed it before.
I'm desperate. I've spent hours scouring every preferences menu I can find and trying everything else I can think of to fix this.
Please, someone, take pity on me.