Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, array must have exactly two members in /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php:308 Stack trace: #0 /home/dh_vzkvx6/mekongstories.com/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array) #1 /home/dh_vzkvx6/mekongstories.com/wp-includes/kses.php(2263): apply_filters('safe_style_css', Array) #2 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-theme-json.php(2767): safecss_filter_attr('gap: 0.5em') #3 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-theme-json.php(1108): WP_Theme_JSON::is_safe_css_declaration('gap', '0.5em') #4 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-theme-json.php(933): WP_Theme_JSON->get_layout_styles(Array) #5 /home/dh_vzkvx6/mekongstories.com/wp-includes/global-styles-and-settings.php(149): WP_Theme_JSON->get_stylesheet(Array, Array) #6 /home/dh_vzkvx6/mekongstories.com/wp-includes/script-loader.php(2434): wp_get_global_stylesheet() #7 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php(308): wp_enqueue_global_styles('') #8 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #9 /home/dh_vzkvx6/mekongstories.com/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #10 /home/dh_vzkvx6/mekongstories.com/wp-includes/script-loader.php(2180): do_action('wp_enqueue_scri...') #11 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php(308): wp_enqueue_scripts('') #12 /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #13 /home/dh_vzkvx6/mekongstories.com/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #14 /home/dh_vzkvx6/mekongstories.com/wp-includes/general-template.php(3043): do_action('wp_head') #15 /home/dh_vzkvx6/mekongstories.com/wp-content/themes/hello-elementor/header.php(21): wp_head() #16 /home/dh_vzkvx6/mekongstories.com/wp-includes/template.php(783): require_once('/home/dh_vzkvx6...') #17 /home/dh_vzkvx6/mekongstories.com/wp-includes/template.php(718): load_template('/home/dh_vzkvx6...', true, Array) #18 /home/dh_vzkvx6/mekongstories.com/wp-includes/general-template.php(48): locate_template(Array, true, true, Array) #19 /home/dh_vzkvx6/mekongstories.com/wp-content/plugins/elementor/modules/page-templates/templates/header-footer.php(9): get_header() #20 /home/dh_vzkvx6/mekongstories.com/wp-includes/template-loader.php(106): include('/home/dh_vzkvx6...') #21 /home/dh_vzkvx6/mekongstories.com/wp-blog-header.php(19): require_once('/home/dh_vzkvx6...') #22 /home/dh_vzkvx6/mekongstories.com/index.php(17): require('/home/dh_vzkvx6...') #23 {main} thrown in /home/dh_vzkvx6/mekongstories.com/wp-includes/class-wp-hook.php on line 308