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 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/class-wp-hook.php:324
Stack trace:
#0 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#1 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#2 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/widgets.php(1862): do_action('widgets_init')
#3 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/class-wp-hook.php(324): wp_widgets_init('')
#4 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#5 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#6 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-settings.php(695): do_action('init')
#7 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-config.php(94): require_once('/data01/virt100...')
#8 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-load.php(50): require_once('/data01/virt100...')
#9 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-blog-header.php(13): require_once('/data01/virt100...')
#10 /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/index.php(17): require('/data01/virt100...')
#11 {main}
thrown in /data01/virt100087/domeenid/www.ahmadiyya.ee/htdocs/wp-includes/class-wp-hook.php on line 324