Slider Not Working

Just upgraded to 3.6.1. A few versions ago, when I ran update on the Calendar plug-in, the slider on my church’s website disappeared. I’ve tried to get it active again and don’t know how. We had a developer create the website, he used Word Press, and he is now longer available to us for help.

Can someone please help me, our website has been down for 6 months.

https://www.ads-software.com/plugins/user-groups/