Error 500

Hey all,

My WP installation has given an error 500 .

This happened a few weeks back and the only way to fix it was to perform a back up of the site.

I don’t want to have to keep doing this so I’m hoping someone can help with this one.

The error log shows the following;

[29-Nov-2020 08:27:57 Europe/London] PHP Fatal error:  Uncaught Error: Call to undefined function wp() in /home/envirofo/deanljbirch.com/wp-blog-header.php:16
Stack trace:
#0 /home/envirofo/deanljbirch.com/index.php(17): require()
#1 {main}
  thrown in /home/envirofo/deanljbirch.com/wp-blog-header.php on line 16

The page I need help with: [log in to see the link]