Hi Danna!
Thanks for getting in touch!
I’m really sorry about your issue. It sure seems strange that is happening.
Was it always showing a 404 page or did it start after you changed something in the site? Let me know.
This could be related to a plugin or theme conflict, so could you please go through the complete steps in this guide > https://theeventscalendar.com/knowledgebase/testing-for-conflicts/ and let me know what you can find in the process?
If you see no difference in those conditions, then we’ll need to do some deeper troubleshooting.
Thanks!
Victor