[Milhouse]

could you please explain what each one of these does?

cache.castthumb = yes: Cache cast artwork yes/no, default no
cache.extrafanart = yes: Cache extrafanart yes/no, default no
cache.extrathumbs = yes: Cache extrathumbs yes/no, default no
cache.hideallitems = yes: If enabled, don't cache Season All artwork, default is no
cache.videoextras = yes: Cache videoextra yes/no, default no. I provided the link a few posts above.

cache.artwork is not a yes/no property, this is the list of artwork types to be cached, ie. cache.artwork=poster,fanart would cache only posters and fanart. Default is to cache all artwork.

I had a situation where actor thumb was ok in movie information page but all the actor thumbs were missing on the actors page (the one that lists all actors in the library). which one of the above commands causes them to go missing?

cache.artwork=yes would only cache yes artwork which obviously isn't a valid artwork type so you'd basically stop caching all artwork, this might have stopped the script caching cast thumbnails.