I've been having the exact same issues as everyone else, but today I couldn't update Pigments through ASC. Other people have recommended going to the resource pages of the synths that didn't download to download the file directly, and I couldn't download it from there either, I kept getting a white blank page. I do server side support where I'm from so I started comparing locations that download and ones that do not, Pigments WIN didn't download but Pigments MAC did, etc. Here is what finally allowed me to download the file...
Solution:
I changed the current link
http://downloads.arturia.net/products/pigments/soft/Pigments_1_1_1_503.exe
to
https://downloads.arturia.net/products/pigments/soft/Pigments_1_1_1_503.exe
and it worked!