(Wordpress) What does this error mean?

I have been trying to create a custom page in my Wordpress theme folder and have a link to it on the navigation. I was told I need make sure this single page can load in the browser. When I typed the address to this page in the browser I got the following error below

Fatal error: Call to undefined function get_header() in /var/www/vhosts/mysite.plesk.freepgs.com/httpdocs/wordpress/wp-content/themes/mytheme/testpage.php on line 1


My first thought was this is a permission related issue, but I went ahead and tried to change the permission from 755 to 777 for the theme folder but no luck. My question is what does this error mean?

 

Basically it means that the code is trying to find the function get_header() and it's not finding it.

 

Do you have something like this in your templates index.php file?

<?php ^M/* Don't remove this line. 
require('./wp-blog-header.php'); ?>

Code (markup):

Q...

 

Could not locate that line in the header.php file in the themes folder. Is that what I'm missing?

 

Yes, you should have that file. If your template didn't come with one, try commenting out the first line on testpage.php