WordPress database error: [Duplicate entry '' for key 'wp_d1ajwbk6t7_blc_links.url_hash']
ALTER TABLE `wp_d1ajwbk6t7_blc_links` ADD UNIQUE KEY `url_hash` (`url_hash`) /* From [enttex.net/sitemap_index.xml] in [/nas/content/live/enttex/wp-content/plugins/broken-link-checker/legacy/includes/admin/db-upgrade.php:408] */