I downloaded and tested both versions you’ve linked to and can confirm that they are indeed not functional. However, I was able to package the game and it load the test map from the menu map without any issues.
So when packaging, did you follow the steps I outlined above? Particularly step 2: (With the menu map open) Under Edit>Project Settings>Maps & Modes: set default and starter map to “Menu” map (save); Then package game.
The steps I’ve listed are all I did to get it to function after opening the project file you sent. If you are performing additional steps, please list them. -Thanks