When turning on OpenLibrarySearch the label OpenLibrarySearch will show last in all search result entries, but nothing will display after it. The web dev tools show an error: XML Parsing Error: not well-formed Location: https://openlibrary.org/search.json?q=de Line Number 1, Column 1:
I see the error in the console, but it seems to work as expected: https://screenshots.firefox.com/sIFImi8m5uXuIrwq/catalogue.kohadev.org
I just retested, the error I saw is no longer there and it works well.