PDF and DjVu files are not handled correctly by HotCats tool, see
Each time you click on a new page a new set of (+)(-) links shows up.
PDF and DjVu files are not handled correctly by HotCats tool, see
It seems to work fine now. This was probably fixed by @Perhelion in https://commons.wikimedia.org/w/index.php?title=MediaWiki:Gadget-HotCat.js&diff=next&oldid=260137498.