[23:46] < yannf> https://commons.wikimedia.org/wiki/File:Map_of_Hindoostan,_1788,_by_Rennell.jpg can't create thumbs? [23:46] < yannf> (big file) [23:49] < yannf> Error creating thumbnail: An unknown error occurred. for all thumbs
Nothing obvious in thumbnail.log related to the file, but that log tends to lack context for the image being processed. @Reedy notes that the image is very large and may exceed the current $wgMaxImageArea setting.