Problem with default scene

hello, so i'm new here, new to unity and i ve got this problem.. i installed unity 2.6.1 and by default it starts with the island demo which worked well until i did something, pushed a button on my keyboard or smtg like that and now on the hierarchy it doesnt show anything. i try to run the game, a big background screen...i tried reinstaling the app, downloading the island demo and recompile but doesnt work...if anyone has any idea how can i solve this :(. thank you!

Besides open the project, you must also open the scene you want to play with (a project can have multiple scenes). The Islands demo only has one scene called Islands. In the project pane , double click on the Islands asset (the one with the Unity logo as icon).