Add script to header.php

We want to post this mail chimp code in our header.php

<script id="mcjs">!function(c,h,i,m,p){m=c.createElement(h),p=c.getElementsByTagName(h)[0],m.async=1,m.src=i,p.parentNode.insertBefore(m,p)}(document,"script","");</script>

but we keep getting

require_once(): Failed opening required ‘includes/wp_booster/sidebar.php’ (include_path=’.:/opt/alt/php56/usr/share/pear:/opt/alt/php56/usr/share/php’)

Old post but there were no responses. FYI, these seem to be unrelated issues.

The require_once() error indicates that there is a file that is not found. Maybe you could uninstall wp_booster to fix this error.

For a Wordpress site, the Mailchimp code should be the last thing in the <head> section. Mailchimp describes this briefly at but it would be better to edit the child theme than to follow their instructions.