PHP Error on new installation

I’ve just installed the plugin on a new website and it is giving the following error in the related posts section of the site;

Notice: Trying to get property ‘ID’ of non-object in /home/sites/11a/0/xxxxxxxxxx/public_html/wp-content/plugins/events-manager/em-events.php on line 299

The page I need help with: [log in to see the link]