Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method OWA_Block::register_widget_sidebar() cannot be called statically in /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/class-wp-hook.php:292 Stack trace: #0 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters('', Array) #1 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/plugin.php(484): WP_Hook->do_action(Array) #2 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/widgets.php(1799): do_action('widgets_init') #3 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/class-wp-hook.php(292): wp_widgets_init('') #4 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters(NULL, Array) #5 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/plugin.php(484): WP_Hook->do_action(Array) #6 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-settings.php(560): do_action('init') #7 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-config.php(81): require_once('/homepages/45/d...') #8 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-load.php(37): require_once('/homepages/45/d...') #9 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-blog-header.php(13): require_once('/homepages/45/d...') #10 /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/index.php(17): require('/homepages/45/d...') #11 {main} thrown in /homepages/45/d192788311/htdocs/clickandbuilds/PaulMaguire/wp-includes/class-wp-hook.php on line 292