Open \wp-content\plugins\contus-video-gallery\front\models\videohome.php and find
public function get_thumdata. Inside the function you can find the following code
SELECT distinct w.*,s.guid,p.playlist_name,p.pid,p.playlist_slugname. If you cannot find
p.playlist_slugname in the above code, please add it. Now go to WP admin -> Settings -> Permalinks -> Set to default and check the site. If it is working fine, then modify the permalink to "postname" and check.
If you are still facing the issue, please contact our supporting team at email@example.com.
And also I have checked your site and noticed that the skin is not displaying in your site. Go to WP admin -> Video Gallery -> Settings. Find "Skin Visible" and enable the option and check.