I was able to visit the download site a few days ago, but it has been unreachable since 17 Sep (CST). I am working on a Macbook and this error was consistent across different browsers.
Could you please help check if the site is indeed down? Or is it possible to circumvent this problem by downloading the data through command line?
The problem here is with brainimagelibrary.org so the solution is to contact them to find out what is going on with their system. You can find their contact information at Brain Image Library: Contact .
I am also going to contact them to determine why this is not working and what their timeline is for fixing the download.