Problem with particles

Hi everyone! I have a problem with particles, look at the images.

The problem is more visible in the first image, particles do a strange effect, like a square.

As you can see the problem is visible in both “Scene” and “Game” windows (so it should not be a problem of the camera), and it affects different particle systems in my game.

I think the problem occurs since I upgraded Unity to the latest version, or so it seems.

Thank you in advance.

Looks like your particle texture is not 100% alpha on the sides. That makes that bad looking cut, make sure you clean up the sides in image editor software.