Fatal error: Uncaught Error: Call to undefined function wp_is_serving_rest_request() in /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php:551
Stack trace:
#0 /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php(461): Yoast\WP\SEO\Integrations\Front_End_Integration->maybe_remove_title_presenter(Array)
#1 /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php(417): Yoast\WP\SEO\Integrations\Front_End_Integration->get_needed_presenters('Post_Type')
#2 /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php(379): Yoast\WP\SEO\Integrations\Front_End_Integration->get_presenters('Post_Type', Object(Yoast\WP\SEO\Context\Meta_Tags_Context))
#3 /home/aliensmalta/public_html/wp-includes/class-wp-hook.php(324): Yoast\WP\SEO\Integrations\Front_End_Integration->present_head('')
#4 /home/aliensmalta/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#5 /home/aliensmalta/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#6 /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php(366): do_action('wpseo_head')
#7 /home/aliensmalta/public_html/wp-includes/class-wp-hook.php(324): Yoast\WP\SEO\Integrations\Front_End_Integration->call_wpseo_head('')
#8 /home/aliensmalta/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#9 /home/aliensmalta/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#10 /home/aliensmalta/public_html/wp-includes/general-template.php(3052): do_action('wp_head')
#11 /home/aliensmalta/public_html/wp-content/themes/understrap-child/header.php(24): wp_head()
#12 /home/aliensmalta/public_html/wp-includes/template.php(790): require_once('/home/aliensmal...')
#13 /home/aliensmalta/public_html/wp-includes/template.php(725): load_template('/home/aliensmal...', true, Array)
#14 /home/aliensmalta/public_html/wp-includes/general-template.php(48): locate_template(Array, true, true, Array)
#15 /home/aliensmalta/public_html/wp-content/themes/understrap/single.php(11): get_header()
#16 /home/aliensmalta/public_html/wp-includes/template-loader.php(106): include('/home/aliensmal...')
#17 /home/aliensmalta/public_html/wp-blog-header.php(19): require_once('/home/aliensmal...')
#18 /home/aliensmalta/public_html/index.php(17): require('/home/aliensmal...')
#19 {main}
thrown in /home/aliensmalta/public_html/wp-content/plugins/wordpress-seo/src/integrations/front-end-integration.php on line 551