[Ipaddle]

Ok, I would suggest to point the add on towards fanart.tv, when searching for movie sets. Anyway, thanks for the information.

Unfortunately that will not make a difference. Talked little bit with fanart.tv guys.
Fanart.TV is intentionally targeted 1:1 at TMDB in order to maintain general compatibility and prevent confusion.
All fanart.tv media id's (Collections, TVShows, Movies) are always without exception the same as TMDB.
Although a bit more autonomy is planned for the next web version of Fanart.TV (use some kind uf sub ID's) this will take some time. 

Ok, I downloaded these collection (eg The Studio Ghibli Collection) fanarts manually from fanart.tv in a folder (defined in the addon), but AB will not find and use them. What is wrong. What did you do?