I'm also unable to download or claim the game while it is currently 100% off. When clicking "Download or Claim", the pop up seems to be set up as if I would pay $0 to add an extra community copy. There is not the usual "click to see downloads" option. And when trying to click to "pay" the $0, an error message appears: "There was an error generating the download URL, please try again." If you're able to resolve this issue, I'd appreciate it. Thanks!
I heard this from a few folks, as best I can tell it was the result of some weird internal interaction between the Halloween sale and the way I used the "add community copies" function when I first published the game. Since this was some error on itch's side, there wasn't much I could do on my end. It didn't seem to affect everyone, strangely, as I had several purchases and downloads during the sale.
In any case I'm adding a bunch of community copies now, please feel free to snag one. If you have any further problems there I'd be happy to send you a download key. Thanks for your interest in the game.