Obstacle doesn't stop player

Hello guys, looking for solving problem with obstacles. I've downloaded the same pack for 2d controller as on this video https://www.udemy.com/2d-game-development-for-unity/learn/lecture/6464492#questions , but put obstacle and hero objects on scene, hero has layer " player" and obstacle has "obstacle", and in settings they both has masks "obstacle" and still have one problem. The problem is, when i push play button "player" just fall down a little bit and disappear, but i did expect him to fall down on obstacle and stop. How do u think where i should seek solving of problem, i have done exactly as on video, but it doesn't work like that.