Students Don't Show Up When Grading
Summary
There are various filters that can change what students show up when grading assignments. You can see in these screenshots that one student did submit the assignment, but 0 of 0 students show up when selecting the Grade button.
Solution
The most common filter that causes the issue is under View all submissions. Again you can see (highlighted in red) that there are no students listed under the assignment. When you look at the First Name and Surname filters (highlighted in green), you can see that Surname is filtering to the letter E. This means only students with the last name that start with E will show up. All students come back by setting these filters to All.
The second common filter that causes issues is under Grade. Looking at the screenshot for the assignment above, we can see there are 10 students. However in the screenshot below, we only see 9 students. By clicking on the filter icon next to "1 of 9", we can see that the filter is only showing the students that did not submit the assignment. By changing this to No Filter, we can see all students.