Hi, you can see on this item tht the link to frwiki is "Gwendoline+Daudet" instead of "Gwendoline_Daudet". This links to a non valid Wikipedia page.
For now, I have replaced "fr:Gwendoline Daudet" by "fr:Gwendoline_Daudet" and the link is now ok. But the problem remains.
See also T148170, T160281, and https://wikidata-externalid-url.toolforge.org.