FYI I have deleted the offending statement in the linked example above and re-added it, in an attempt to trigger a reindexing.

Sure thing. I can see statement P14 ("formatted citation") for the following item with the UI in my browser: https://ppsdb.wikibase.cloud/wiki/Item:Q1095

I'm experiencing this issue too. For my Wikibase I wrote a wikibaseintegrator script to find items with property P13 but not P14 using a SPARQL query, then add a P14 statement. However, the SPARQL query (https://tinyurl.com/2y9nxtk6) returns some items that already have a P14 statement, such as https://ppsdb.wikibase.cloud/wiki/Item:Q1095

Starting experiencing this "An error has occurred while searching" problem today (2 Apr 2024) with the search page on ppsdb.wikibase.cloud, which was previously not affected.

Hello, chiming in here to say that this affects my instance at ppsdb.wikibase.cloud too, and several other users, reported in the Telegram chat.

Thank you for your help! PDF is OK, I must have typed in the .djvu file extension by mistake.