That's logical why it throws 404 because when u're in home page (as a reference) the about page is inside htmlPages folder and that works fine, but when you are in about page it means you are no longer in src folder but instead you are in src/htmlPages it means when you click the about.html link it tries to take you to src/htmlPages/htmlPages/about.html but instead it should take you to src/htmlPages/about.html. So to fix this you should go to your about.html and change the link from htmlPages/about.html into about.html