Same problem with the 64 bit version also. I tried Edge and Chrome, but to no avail. I downloaded the app, but, alas, no. It keeps saying that the connection was forcibly closed by the remote host. Ugh. I hope they get this resolved...
Edit!
I googled "cannot download raft", and someone in another post pointed to an alternate download method. I kept trying through the app, and eventually, it finished.
I don't know if it'll work for all, but here's what I found:
https://itch.io/t/55138/i-cannot-download-installe...
The beauty of the app is that it (I believe) picks up the download where it left off, so if you're diligent enough, you'll eventually get all of it.
Hope this helps, guys...