Hello,
I’m sorry that you’re running into this issue, but I’ll be happy to help you figure out what’s going on!
I took a look at the page you linked to, and everything appears to be working correctly on my end. Can you please provide some more details on what is going wrong with the calendar? Did this happen after you updated our plugins or something else on your site?
If you are still seeing this issue, the first troubleshooting step would be to run through the instructions outlined here to check for any conflicts that might be occurring with your theme or another plugin. Please make sure to have WP_DEBUG enabled while testing and copy/paste any errors that you see into your reply.
Thanks,
Jennifer