As an admin of your content on WordPress, seeing a 404 error when you try to access your posts can be a scary moment. No panic! You content is most likely still there. You just need to make some tweaks to fix the problem.
Here is a video that shows you what to do:
For more detailed information, the article “How to Fix WordPress Posts Returning 404 Error” provides step-by-step instruction to help you fix the issue.