External page integrated into WordPress returns a 404 error
You should be including wp-load.php, not wp-blog-header.php (which is reserved for use by WordPress only). This is most likely the cause of your problem.
You should be including wp-load.php, not wp-blog-header.php (which is reserved for use by WordPress only). This is most likely the cause of your problem.
Go to settings->permalinks and click on save button to rewrite flush. And then empty your browser cache. It’ll work hopefully.