Why, when I press “yes” on the safety notification (to bear own responsibilità) nothng happens? How to erase that black image, wihch is itself dangerous, since it occupies almost  all the screen?

Tick the box then press yes.

Can you send some screen shots please.

As Aardvark says, there is a tick box, its very, very hard to see, its on the right side of the text...

Please refer to the answers above, kindly tick the box then yes.