Fatal error: Call to undefined function vc_map_get_attributes()

Hi,
When i installed the theme, and imported the demo xml.txt file everytime i click on the pages added to view it i get this error
Fatal error: Call to undefined function vc_map_get_attributes() in /home/e7prod/public_html/wp-content/themes/fortuna/includes/shortcodes/vc/boc_heading.php on line 11

I have checked another post similar to this, but a lot of the replies have been set private to it so i couldn’t figure out the solution, and i have removed the existing theme i been using before Fortuna, Plus my WordPress is on the latest version, Please i need some help! Thanks