How odd. I got the same error that you do. It starts loading and then in the console it turns red.
I tried to visit the Category Page directly:
https://ca.ctrinstitute.com/workshops/category/crisis-response-planning/
And get a 500 Internal Server Error. Do you get the same error? Is that the correct link for that Event Category?
If so do you have security plugins or htaccess coding that might cause this issue?
IF you can remove crisis from the slug does that solve anything?
For example change the slug for the Event Category to /response-planning/ and see if that helps.
Let me know what you find out and we can go from there.
Thanks