WordPress call to undefined function get_header();

Question

Firstly, I have looked for previous posts about this topic, but none have the answer that I need. So I shall rephrase to fit my problem best.

I\'m taking my first cr

Answer 1

Generally this happens when someone has mistakenly put index.php from a theme in the WP install folder, where it overwrites the index.php that is the main WordPress file.

That is, the index.php that lives in the root directory (thats the directory with the wp-config.php in it) is NOT an editable theme file.