Hello everyone!

There are two pieces of good news and bad news.

The good news is that I've found the problem.

The bad news is that to fix it, I'll either have to write to support or try to fix it myself. 

The thing is that I created "rewards" in a test version, and at that point a couple of people made a purchase of the game. Now I can't get rid of these "rewards", I can only hide them. In fact, this is why the download buttons have disappeared. 

As soon as I solve the problem I'll let you know. Wish me luck.