"PHP message: WordPress-Datenbank-Fehler Duplicate entry '0' for key 'PRIMARY' für Abfrage INSERT INTO `wp_sitemeta` (`site_id`, `meta_key`, `meta_value`) VALUES (1, '_site_transient_update_core', 'O:8:"stdClass":3:{s:7:"updates";a:0:{}s:15:"version_checked";s:5:"4.9.1";s:12:"last_checked";i:1513010598;}') von require_once('wp-admin/admin.php'), do_action('admin_init'), WP_Hook->do_action, WP_Hook->apply_filters, _maybe_update_core, wp_version_check, set_site_transient, add_site_option, add_network_option