Wikibase Cloud discovery page fails with the error: Failed to collect Wikibase stats. This was first reported by a user on telegram on April 9th.
See screen shot:
This is due to a 500 from the platform api from the request to https://api.wikibase.cloud/wiki?sort=pages&direction=desc&is_active=1&page=1&per_page=24
What I can see in the logs is entries like
[2024-04-16 14:15:04] production.ERROR: SQLSTATE[21000]: Cardinality violation: 1242 Subquery returns more than 1 row (Connection: mysql, SQL: select * from `wikis` where exists (select * from `wiki_site_stats` where `wikis`.`id` = `wiki_site_stats`.`wiki_id` and `pages` >= 2) and `wikis`.`deleted_at` is null order by (select `pages` from `wiki_site_stats` where `wiki_site_stats`.`wiki_id` = `wikis`.`id`) desc limit 24 offset 0) {"exception":"[object] (Illuminate\\Database\\QueryException(code: 21000): SQLSTATE[21000]: Cardinality violation: 1242 Subquery returns more than 1 row (Connection: mysql, SQL: select * from `wikis` where exists (select * from `wiki_site_stats` where `wikis`.`id` = `wiki_site_stats`.`wiki_id` and `pages` >= 2) and `wikis`.`deleted_at` is null order by (select `pages` from `wiki_site_stats` where `wiki_site_stats`.`wiki_id` = `wikis`.`id`) desc limit 24 offset 0) at