Hi Colin. I assume you're trying to follow the instructions on https://download.intersystems.com/download/atelier.csp.

Under Step 2 => #3 it says you have 2 options for installing Atelier. As you've found out, the first option isn't working right now. Try the 2nd option, which starts: "II. Add one of the Atelier repositories to your Eclipse environment "

That worked for me.