Problem Description:
In line 238 of the management_renderer.php file, an icon is created, but in Moodle (Boost theme), the icon is not displayed correctly. Instead, a blank space appears where the icon should be.

Steps to Reproduce:

1. Go to Site Administration → Courses → Manage courses and categories.
2. View the list of categories.
3. Notice that there is a blank space, but the icon does not appear.

Let me know if you need any adjustments!