I'm having some trouble in validating my website.
I am using a framework of Codeigniter. I tried to validate my website using this link https://validator.w3.org/nu/ but it always an IO error and then I try to remove all my files and I just put some simple html in my index file and it works. Meaning I have some trouble in my Codeigniter. Any suggestion will do the help thank you.
You are trying to validate server-side script which cannot be validated by W3 validation. So either you need to host your project and provide address for validation or you can simply validate the views(front-end stuff) in the website. Hope this helps.