OnTriggerEnter2D doesnt work

Unity Engine
1

Hello. I am programming a simple game with unity 5.5.0f3. The game is PONG.
The game is almost finished but i have found a problem at the final.
The problem is the following, when the ball touch the walls it bounces without problem, but the method OnTriggerEnter2D doesnt execute his code, it is like if doesnt detect collision. I want that when te ball collisions with right or left wall the player adds one point.
I have uploaded my project.
Thanks to all.

2942772–217832–Pong 2017.rar (909 KB)

2

Use the void “OnCollisionEnter2D”

3

it doesnt work, it launches a warning message:

There are inconsistent line endings in the ‘Assets/SideWalls.cs’ script. Some are Mac OS X (UNIX) and some are Windows.
This might lead to incorrect line numbers in stacktraces and compiler errors. Many text editors can fix this using Convert Line Endings menu commands.

and a error message:

Script error: OnCollisionEnter2D
This message parameter has to be of type: Collision2D
The message will be ignored.