A 404 error tells you that the page or file you are trying to open can't be found. If you have a lot of 404 errors on your WordPress site, then this is often due to an issue with your .htaccess file and that can be remedied by updating your permalinks. Follow the steps below to fix this.
- Log in to WordPress admin.
- Click Settings > Permalinks in the menu on the left.
- Click Save Changes at the bottom of the page.
- Click Purge Performance Cache at the top of the screen, if you have this enabled. Do the same for other caching plugins you may have.