I can access the album just fine, but I am logged in into my account. It seems to indeed give a dead link for other people, since I tried accessing it in an Incognito tab, and indeed got an [404] ‘The requested page could not be found’ error as well.. 
Since I couldn’t find any way to fix it in the album settings, I’ve opened a issue request on Imgur, so they can hopefully fix it..
Iirc, the album was once (many years ago when I first shared it) reported as 18+ content. Whether it was manually by someone or automatically by the system, I dunno, but that might have something to do with it. I know @joponnes mentioned they got an 18+ warning when accessing it over a year ago:
Maybe accessing the link without an imgur account gives a 404 altogether, instead of suggesting to log in to see the supposedly (incorrect) 18+ content. 
Back to the topic, one additional limit I have with all my collections I forgot to mention, both TCG and non-TCG: I don’t care about duplicates. I like different languages, and very minor variations, but exact duplicates not. Kinda related to this earlier QotD: QotD: Do you feel the need for duplicates of your favorite cards? - #7 by Quuador.
Greetz,
Quuador