Uncaught Error: Call to undefined function get_header() No Code Change

Hello,

I’m rebuilding a website for someone and making a theme from scratch, I wanted to add some code in the footer.php file so I did then I FTPed the theme back accross and I get the following error.

Fatal error: Uncaught Error: Call to undefined function get_header() in /homepages/24/d634280769/htdocs/tynronglenshaw.com/dev/index.php:9 Stack trace: #0 {main} thrown in /homepages/24/d634280769/htdocs/tynronglenshaw.com/dev/index.php on line 9

I have looked inside the index.php file in my theme and nothing has been changed. I have also looked at header.php but again nothing changed. The last code edits I made to those files were a few days ago.

I removed the code that I put into the footer.php. I don’t know why it’s not working.

Duncan