Here is an example of warnings appearing in the gradebook: 

This could be caused by several things:

- In the example above, the simple problem is that grades are entered for the Homework and Review type, but no Assignment Weight combinations exist for these.

- Another likely possibility is that there are grades entered for the student in another group for the same subject. For example, if these students were in the 4th Grade group and also in the 4th and 5th Grade group, and grades were entered for both in Math, it would cause these issues. This can be harder to spot as the averages are sometimes simply wrong.

- Although this is a much rarer occurrence, it is possible that the database has grades for this student in this subject, but assigned to a group he is not even part of.

- Another rare occurrence is that a student was not assigned to any primary student groups. (https://zammad.olivetree.software/help/en-us/7/153)