I'm having similar problems. I just downloaded the latest itch launcher and downloaded the game through the launcher. When you go to launch the game, it prompts to install Microsoft Visual C++ runtime, so i click yes. That brings up the UE4Prereq x64 Setup. And that installs successfully. And then nothing happens after that. You go to relaunch the game, it prompts again the C++ requirement, and sends you into the UE4Prereq setup again, this time you can either uninstall it or cancel. Just wondering what i'm doing wrong.