I should perhaps have told you where the black screen occurs. It happens after the screen where I can see my pokemon and then press any button to load the world, before I see my character. (I don't know how I even managed to forget this, terribly sorry).
So I tried again, and now this happened:
I tried to do something different. I downloaded the game from scratch, with patch and game. Then I put in the Game.rxdata in to those files and tried to load the game. After getting the first "The script is taking too long, the game will restart", I saved. And now it says that the map is corrupt. (Which didn't happen with the other maps of Rejuvenation that I have).
I know that you just said that you are not familiar with Mac nor Wine, but if you are able to connect this to anything, then perhaps we could fix it anyways.
And if not, well, pokemon Reborn will be out soon anyways (I hope...).
Thank you for trying to help!
Edit: The game goes back and forth from being able to open and then not being able to open. But currently it works again. I have no idea what caused the problem, nor what fixed it. So that is just great.