I am using Windows and have TSW4 installed in a Steam library on one SSD and now installed the editor on another SSD. The editor does not find the game location but does not offer me the option to choose the directory in which the game files are residing in. By default, the editor wanted to be installed on an HDD. Probably, because that path is somewhere in the registry for EpicGames. That's really an unfortunate situation because it prevents me from using the editor despite fulfilling all criteria. I have zero problems starting the normal UE4 editor from Epic Games. Update: So, I now uninstalled the editor again and installed it directly besides the TSW4 installation. I even added it as a non-Steam game to the Steam library and then modified the CLI parameters to include "TS2Prototype -Installed". Then it actually booted up and after waiting forever on shader compilation, the editor window finally was visible.
