Plugin causing problems

I’ve had My Calendar installed on this site for a few months, and all of a sudden it started causing problems. If I deactivate this plugin, the site comes up, with the plugin active, only the sidebar shows up. The site uses the Unik theme. I updated all the plugins a few days ago, and everything seemed to continue to work fine, no conflicts. How do I troubleshoot this?

https://ww.wp.xz.cn/plugins/my-calendar/