Hey Danielle,
Sorry to hear about the troubles. When attempting to access your Past Events page, it appears there is some kind of conflict going on. I recommend reading through our Testing for conflicts article on how to address that. This will be the first thing you need to do in order to get the events to display properly.
And we need to include pages that list past events for each category.
Can you provide a little more detail on what you’re trying to accomplish? If you’re trying to add a link to past events for a category, simply visit the category page, select “Previous Events”, then copy and paste that URL into a menu item custom link and name it whatever you’d like.
I hope this information helps and thanks for choosing PRO!