Problem opening projects downloaded from unity site!!!

I've got an indie version of unity 2.6.1 and I downloaded the 2DGameplay Tutorial Project from the unity site. But when I try to open it in Unity, a window pops up saying that the project was created with a previous version of unity and that it needs to be "updated". Then, I got an empty scene, all the prefabs and the assets with missing scripts and mesh filters, materials without the textures and so on.when I try to use one of the scripts in another project, it says that the script is incomplete. The same thing with "Detonator" and other tutorials. The question is: WHY????! Helpme please

Try upgrading to the newest free version of Unity and see if you have the same problems: