Sorry for my late response! Did you just download the launcher? Or did you already download it in the past? There was an issue one year ago which couldn't be fixed by an automatic update unfortunately, so if you've downloaded the launcher back then, it's necessary to download it again
However, if you've just downloaded the launcher and it still doesn't work, it could be a permission issue
If the launcher has no write permission, Mac launches it in a temporary folder instead, preventing the game from downloading any files.
To fix this, you can try to create a new folder "Rising World" under "Applications" and put the launcher there, then try to launch it. Does the issue still occurs?
No problem! After going in my System Settings and allowing Rising World to be installed on Mac, I created a new folder "Rising World" in my Applications folder and put the launcher in that folder, then launched it. It works, thanks! On Sequoia