Error – mt1.post_id IS NULL

Hello,

since few days getting below error constantly.

Can any one tell the reason for errors.

[06-May-2020 17:52:12 UTC] WordPress database error Lost connection to MySQL server during query for query SELECT sbif_posts.ID FROM sbif_posts LEFT JOIN sbif_postmeta ON ( sbif_posts.ID = sbif_postmeta.post_id ) LEFT JOIN sbif_postmeta AS mt1 ON (sbif_posts.ID = mt1.post_id AND mt1.meta_key = ‘_aioseop_noindex’ ) WHERE 1=1 AND (
( sbif_postmeta.meta_key = ‘_aioseop_noindex’ AND sbif_postmeta.meta_value != ‘on’ )
OR
mt1.post_id IS NULL
) AND sbif_posts.post_type = ‘product’ AND ((sbif_posts.post_status = ‘publish’)) GROUP BY sbif_posts.ID ORDER BY sbif_posts.post_date DESC made by require(‘wp-blog-header.php’), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts, WP_Query->parse_query, do_action_ref_array(‘parse_query’), WP_Hook->do_action, WP_Hook->apply_filters, All_in_One_SEO_Pack_Sitemap->sitemap_output_hook, All_in_One_SEO_Pack_Sitemap->do_rewrite_sitemap, All_in_One_SEO_Pack_Sitemap->do_build_sitemap, All_in_One_SEO_Pack_Sitemap->get_sitemap_data, All_in_One_SEO_Pack_Sitemap->get_sitemap_index_filenames, All_in_One_SEO_Pack_Sitemap->get_all_post_counts, All_in_One_SEO_Pack_Sitemap->get_post_count, WP_Query->__construct, WP_Query->query, WP_Query->get_posts
[06-May-2020 22:49:56 UTC] WordPress database error Lost connection to MySQL server during query for query SELECT sbif_posts.ID FROM sbif_posts LEFT JOIN sbif_postmeta ON ( sbif_posts.ID = sbif_postmeta.post_id ) LEFT JOIN sbif_postmeta AS mt1 ON (sbif_posts.ID = mt1.post_id AND mt1.meta_key = ‘_aioseop_noindex’ ) WHERE 1=1 AND (
( sbif_postmeta.meta_key = ‘_aioseop_noindex’ AND sbif_postmeta.meta_value != ‘on’ )
OR

Thanks