Steps to reproduce:
Set up a calculation for the course total (for example at http://demo.moodle.org/course/view.php?id=2)
Go to Edit categories and items
Click on edit icon for the top level category
The Advanced button is not printed
This gets confusing for users, who forget they set up a course total calculation and now are trying to change the category settings
It would be better to have an indication printed here - "Advanced not shown due to calculations being used in the Course Total".