Fatal error: Call to undefined function mfn_tag_schema() in /home/DOMAINNAM/public_html/wp-content/t
Whenever I go to my page, the following comes up (I took out the domain):
Fatal error: Call to undefined function mfn_tag_schema() in /home/MYDOMAINNAME/public_html/wp-content/themes/betheme/header.php on line 15
And I don't know how to access the builder.
please update theme to latest version because looks like your theme is not complete. But Muffin Builder is in "Page options" section while you create/edit page in wordpress.