The server software must be associated with a project in order to be able to run. When run from the Editor menu, the currently open project is used by the server. To run the server independently from the editor, select "Editor > Select Tools > Create Server Files to specify a folder and copy the server files to this folder. The "ServerEngine" script is used to launch the server. The "ServerEngine" script looks for a folder named "Project" in the same folder as the default behavior.