I can't get any not default modpacks to work

[Jarsupial]

I tried downloading enderclan and it kept saying error downloading and it wouldn't work. So then I tried getting An Architects dream and adding that one instead. I followed the instructions, copy URL, click ADD NEW MODPACK, pasted URL, hit launch. It starts to say it's updating but it never moves off of 0% then it launches right away, faster than it should if it was getting a new pack, and when I launch it's just vanilla MC. No new additions or anything have been added and I'm wondering what I should do to fix the problem. I really just want to build cool stuff on creative mode and it's frustrating.