PHP Notice:  Undefined index:  addthis_showonexcerpts in /wp-content/plugins/addthis/addthis_social_widget.php on line 1206
Ln 1206 change to:
        if (empty($options['addthis_showonexcerpts']))
        
PHP Notice:  Undefined index:  above in /wp-content/plugins/addthis/addthis_social_widget.php on line 1402
Ln 1402 change to:
            if (!empty($options['above']) && $options['above'] == 'custom')
            
PHP Notice:  Undefined index:  below in /wp-content/plugins/addthis/addthis_social_widget.php on line 1409
Ln 1409 change to:
            if (!empty($options['below']) && $options['below'] == 'custom')