The problem of using Events module

I use Events module, and module layout by default. When I click icon of category on Event module, I get "Fatal error: Call to undefined method EasySocialModelEventCategories::getImmediateChildCategories() in /hd2/.XDATA/home/scs/_www_/components/com_easysocial/views/events/view.html.php on line 1905 ".

By the way, when I use layout by card, I can't see category icon displayed on the module in the front-end.