When installing a new website we had errors when trying to make settings for Cloudflare. The error message said:

To fix this we had to disable Wordfence by commenting out its lines in the .htaccess file:

# Wordfence WAF
#
#        php_value auto_prepend_file '/var/www/html/sites/events/summit2018/wordfence-waf.php'
#

Once the connection was made, you can uncomment the lines above in the .htaccess file.