How To Reset Permalinks For Posts
If you are receiving 404 pages when you try to open a blog or portfolio post, you may need to reset your permalinks. To do this, follow the steps below.
Step 1 - Navigate to Settings > Permalinks in your WordPress Admin.
Step 2 - Check the common settings to see what you have selected, then scroll to the bottom and click "Save Changes".
Step 3 - Refresh your page and see if it works. Make sure to clear all forms of cache. That could be plugin cache, browser cache and/or server cache. More info on clearing cache can be found here. If that does not fix it, please see additional information below.