Fatal error: Uncaught Error: Non-static method NextGEN_shortcodes::convert_shortcode() cannot be called statically in /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/nextcellent-gallery-nextgen-legacy/lib/sitemap.php:41
Stack trace:
#0 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp-hook.php(341): nggSitemaps->add_wpseo_xml_sitemap_images(Array, 564)
#1 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)
#2 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/wordpress-seo/inc/sitemaps/class-sitemap-image-parser.php(127): apply_filters('wpseo_sitemap_u...', Array, 564)
#3 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/wordpress-seo/inc/sitemaps/class-post-type-sitemap-provider.php(664): WPSEO_Sitemap_Image_Parser->get_images(Object(WP_Post))
#4 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/wordpress-seo/inc/sitemaps/class-post-type-sitemap-provider.php(211): WPSEO_Post_Type_Sitemap_Provider->get_url(Object(WP_Post))
#5 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/wordpress-seo/inc/sitemaps/class-sitemaps.php(379): WPSEO_Post_Type_Sitemap_Provider->get_sitemap_links('werk', 1000, 1)
#6 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/wordpress-seo/inc/sitemaps/class-sitemaps.php(279): WPSEO_Sitemaps->build_sitemap('werk')
#7 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp-hook.php(341): WPSEO_Sitemaps->redirect(Object(WP_Query))
#8 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters('', Array)
#9 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/plugin.php(570): WP_Hook->do_action(Array)
#10 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp-query.php(1910): do_action_ref_array('pre_get_posts', Array)
#11 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp-query.php(3958): WP_Query->get_posts()
#12 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp.php(704): WP_Query->query(Array)
#13 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/class-wp.php(824): WP->query_posts()
#14 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-includes/functions.php(1343): WP->main('')
#15 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-blog-header.php(16): wp()
#16 /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/index.php(17): require('/home/httpd/vho...')
#17 {main}
  thrown in /home/httpd/vhosts/erhardsigrist.ch/bernhardannen.net/wp-content/plugins/nextcellent-gallery-nextgen-legacy/lib/sitemap.php on line 41