In Moodle, every activity module plugin is required to have pix/icon.png (and optionally pix/icon.svg). Moodle's plugin API resolves the plugin icon through pix_icon and get_icon_url() using the path pix/icon by convention, without explicit code reference needed. The icon appears in the activity chooser, course page and admin interfaces.
This applies to any Moodle plugin of type mod: the file must exist or the plugin will display a broken/missing icon throughout the Moodle UI.
In Moodle, every activity module plugin is required to have pix/icon.png (and optionally pix/icon.svg). Moodle's plugin API resolves the plugin icon through pix_icon and get_icon_url() using the path pix/icon by convention, without explicit code reference needed. The icon appears in the activity chooser, course page and admin interfaces.
This applies to any Moodle plugin of type mod: the file must exist or the plugin will display a broken/missing icon throughout the Moodle UI.