Add wp_body_open() to your theme
Added for backwards compatibility to support WordPress versions prior to 5.2.0.
if ( ! function_exists( 'wp_body_open' ) ) { /** * Fire the wp_body_open action. * * Added for backwards compatibility to support WordPress versions prior to 5.2.0. */ function wp_body_open() { /** * Triggered after the opening <body> tag. */ do_action( 'wp_body_open' ); } }