Recently I decided to change one of my permalinks on my site from /tests to /reviews. I also set up a redirect on cPanel to redirect any traffic from /tests to /reviews this is essential as Google has already indexed /tests so setting up a 301 redirect will tell Google the page has moved and avoid a nasty 404 page not found error.
However this didn’t work once I made the redirect in cPanel I got a Word Press 404 error for both /tests and /reviews! This is because the redirect rule in your .htaccess file is added at the bottom of the file after Word Press’s mod rewrite rules. Simply add the cPanel redirect rule above the Word Press mod rewrite rule and all shall be fixed again.