Can not start the game at all , it shows game crash error on the screen .

Hi , 

I have just purchase  mine craft game from Official  web site https://www.minecraft.net/ , then did the download on the computer , then try to play . It didn't start at all . I did restart the computer , we do have a very good internet connection 300 MB . The game start to activated but stopped in the middle and on the screen it shows game crash.

Thank you 

Elena