I just downloaded and open it. And I looks like this. Should I do something on the setting? When I pressed play, all the meshes are there. Please heeelp 
Don’t panic! It is because the world is not loaded!!
In the world partition, you can activate whatever cells you’d like
And in case you are looking for the Dark world just activate the layers:
And well I do not recommend activating all cells, by logic…
Thanks a lot! It works fine now!