Near and collision don't work

Collision and near sensors don’t work properly.Here is the game i am making.Press left mouse button to fire at the largest cube.Was something changed?I have blender 2.74 windows 64 version.

Your file is not a very good example of the problem:

  • You do not explain what you expect to happen vs what is happening for you
  • You have lots of files with poor names, many objects with logic bricks
  • Difficult to interact with player

In future, upload a simple, single-to-few object file, and write in the text window, or the post, what the issue is.

I tested the file in Windows 7 64bit, Blender 2.74, and shooting the cube caused an explosion effect. Was this what you expected?

Enable actor on the objects you want it to detect.

Collision sensor does not work but near sensor does.I had to increase it’s range.I guess i will have to use near sensor instead.

I didn’t look at your blend, but.
I noticed the same thing with collision. So I use near.
Giving the object a collision bounds seemed to work for me.