Based on the amount of times you missed the c from the word project… my first recommendation would be to check for typos in your code/file names 🙂

Try updating permalinks in here: /wp-admin/options-permalink.php. Just hit update, and see if that solves the problem.

Also, see if any errors are getting reported, open up wp-config and change define('WP_DEBUG', false); to true. Then try your single page again and see if any errors come back.

You could also check your PHP error logs for any signs.