Why Site.pro website builder plugin icon is not visible if I use cPanel's "paper_lantern" theme?

cPanel installation uses custom style for "paper_lantern" theme (this can be verified by looking in folder /var/cpanel/customizations/styled/ that will contain folders with style name). To solve this issue call this command: "/usr/local/cpanel/bin/sprite_generator --theme paper_lantern --style [style_name] --verbose" as root in server cPanel is installed ("[style_name]" in this command needs to be replaced with a name of a style folder you want to fix).