No artwork in collections

[zero0]

Hello,
I have a large collection that was created automatically, but none of them have any artwork or description. 
The movies inside the collections have artwork and are correctly grouped, but the collections themselves do not have any artwork at all. I can't figure out what I'm doing wrong.
Any help would be appreciated.

[TheDreadPirate]

I'm assuming you used the collections function in the library settings. I'd recommend turning that off and installing and using the TMDB Boxset plugin. That should pull down Collection images.

[zero0]

Yes, you are right and TMDB Boxset plugin worked as expected.
Thank you for your quick reply.