Thread: How to fix 404 errors in WordPress permanently without plugins?

How to Fix WordPress Posts Returning 404 Error

Step 1: Reset Your WordPress Permalinks
Step 2: Restore Your .htaccess File
Step 3: Disable All of Your WordPress Plugins and Theme
Step 4: Set Up a 301 Redirect for Moved or Renamed Content

For more, Read this “How to Fix WordPress 404 Error”