Also.. per Uhrwerk's suggestion, I uninstalled the program, deleted the folder, reinstalled everything from scratch and tried again. This time, I also created a new project (outdoor project via the project wizard). Once the project was finished and it loaded the map for me, again I built the map, clicked on the "run" button and, again, I get the same error, the error in main.sys, only it only happens once with a clean new project build.