Category Links Not Working After Upgrade

I upgraded to the new 2.5 today. Everything went well, except my category links aren’t working. Those categories are there in the admin panel, but they don’t work on the actual website. Check it out:

https://www.trishabartle.com/

As you can see, the “Topics” are all there. When you click on them, it brings you to the 404 page. Except for the “Writing Samples” Parent, which brings you to only one of the many posts that should be in that category.

I can’t figure out the problem.

Any help is appreciated.