We have an education course page created using the EducationProgram extension. All our students created new Wikipedia accounts yesterday, but one of them is not appearing in the student list despite having clicked the "Enroll" button multiple times. The student does appear in the "Activity for course", and looking at their username logs shows them as a student on our course. No other students in the same or subsequent classes yesterday had this problem and no student in previous years has had this problem.

I am an instructor for this course, but I cannot add the student via the "Add students to this course" section at the bottom of the course page. I tried with both Chrome and Firefox. I get the error:
"While adding students, the following error occurred: $1.internal_api_error_DBQueryError"

This is the course page: https://en.wikipedia.org/wiki/Education_Program:University_of_Portsmouth/Applied_Human_Geography_(Spring_2017)

This is the student user: https://en.wikipedia.org/wiki/Special:Log/MNicholas46

Thanks in advance for any help with this.