We'll create fresh WordPress site with MP smart redirect: Simple 404 redirecter, without entering 404 pages and redirects! installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Simple plugin to redirect your old URL’s that give a 404 to their new URL. For example: you deleted some categories and changed the permalink structure -> WordPress isn’t redirecting your posts to the right page and gives a 404, your old URL was dead-category/my-page.html and it’s now /my-page.html. This plugin fixes this issue and creates a 301 redirect to your right url. We don’t save any data to your database! So we also don’t create logs of your 404’s. You can use a different plugin for that like Redirection (recommended to install since you can view and add redirections this plugin might missed).