SermonSpeaker front-end stopped working

We started getting a 404 error on our Joomla site whenever we try to browse sermons. My Joomla/PHP knowledge is very basic, so I'm not really sure what I need to do to troubleshoot. I did ensure everything is up-to-date and tried reinstalling the SermonSpeaker add-ins.

URL: gracechapelwl.org/sermons
(Note: The Latest Sermons module has also disappeared from our Home page, and all of the different links under Sermons, as well as any direct links to specific sermons all result in 404 errors.)

Since the error message is "Category not found", I'd first check on that one. So check that the category set in the menu item is a published and public SermonSpeaker category.
Also make sure each series, speaker and sermon has a category assigned which is published and public.
Those are all checked for permissions and if any is unpublished or trashed, SermonSpeaker will do as if it doesn't exist.

That was too easy - it was staring me right in the face and I still missed it! We just have everything under the "Uncategorized" category, so I didn't pay much attention to the fact that it wasn't published. Published that category and everything started working again! Thanks!

Great to hear that it was such a simple cause!