Na czym polega korekta lakieru?

Fatal error: Uncaught Error: Call to undefined function mfn_builder_print() in /home/souczek/domains/souczek-detailing.com/public_html/wp-content/themes/betheme-child/includes/content-single-child.php:227 Stack trace: #0 /home/souczek/domains/souczek-detailing.com/public_html/wp-includes/template.php(792): require() #1 /home/souczek/domains/souczek-detailing.com/public_html/wp-includes/template.php(725): load_template('/home/souczek/d...', false, Array) #2 /home/souczek/domains/souczek-detailing.com/public_html/wp-includes/general-template.php(206): locate_template(Array, true, false, Array) #3 /home/souczek/domains/souczek-detailing.com/public_html/wp-content/themes/betheme-child/single.php(60): get_template_part('includes/conten...', 'single-child') #4 /home/souczek/domains/souczek-detailing.com/public_html/wp-includes/template-loader.php(106): include('/home/souczek/d...') #5 /home/souczek/domains/souczek-detailing.com/public_html/wp-blog-header.php(19): require_once('/home/souczek/d...') #6 /home/souczek/domains/soucz in /home/souczek/domains/souczek-detailing.com/public_html/wp-content/themes/betheme-child/includes/content-single-child.php on line 227