Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class "WP_Duotone" not found in /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/class-wp-hook.php:308 Stack trace: #0 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array) #1 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/blocks.php(503): apply_filters('block_type_meta...', Array, Array) #2 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/blocks/legacy-widget.php(62): register_block_type_from_metadata('/data/4/0/113/1...', Array) #3 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/class-wp-hook.php(308): register_block_core_legacy_widget('') #4 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #5 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #6 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-settings.php(623): do_action('init') #7 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-config.php(87): require_once('/data/4/0/113/1...') #8 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-load.php(50): require_once('/data/4/0/113/1...') #9 /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-blog-header.php(13): require_once('/data/4/0/113/1...') #10 /data/4/0/113/120/276446/user/280739/htdocs/examples/index.php(17): require('/data/4/0/113/1...') #11 {main} thrown in /data/4/0/113/120/276446/user/280739/htdocs/examples/wp-includes/class-wp-hook.php on line 308