Fatal error: Uncaught Error: Undefined constant "HEADER" in /usr/home/rrm/domains/pix.edu.pl/public_html/wp-content/themes/sparkling/inc/custom-header.php:56 Stack trace: #0 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/class-wp-hook.php(288): sparkling_header_style('') #1 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/class-wp-hook.php(312): WP_Hook->apply_filters(NULL, Array) #2 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/plugin.php(478): WP_Hook->do_action(Array) #3 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/general-template.php(2879): do_action('wp_head') #4 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-content/themes/sparkling/header.php(30): wp_head() #5 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/template.php(722): require_once('/usr/home/rrm/d...') #6 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/template.php(671): load_template('/usr/home/rrm/d...', true) #7 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/general-template.php(41): locate_template(Array, true) #8 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-content/themes/sparkling/404.php(8): get_header() #9 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-includes/template-loader.php(98): include('/usr/home/rrm/d...') #10 /usr/home/rrm/domains/pix.edu.pl/public_html/wp-blog-header.php(19): require_once('/usr/home/rrm/d...') #11 /usr/home/rrm/domains/pix.edu.pl/public_html/index.php(17): require('/usr/home/rrm/d...') #12 {main} thrown in /usr/home/rrm/domains/pix.edu.pl/public_html/wp-content/themes/sparkling/inc/custom-header.php on line 56