Projecting hole in Unity 5

I got the shader from here http://forum.unity3d.com/threads/projecting-a-hole.35808/

But it does not seem to work on unity 5.

I don't know pretty much anything about shader scripts, so can somebody explain what is the problem with this shader?

 Shader "DepthMask Projector"
 {    
     Properties
     {
         _MainTex ("Cookie", 2D) = "gray" { TexGen ObjectLinear }
         _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
     }
     
     SubShader
     {
         Tags {"Queue"="Geometry-100" }
 
         Lighting Off
 
         ColorMask A
         
         Pass 
         {
             ZWrite On
             ZTest Less
         
             Alphatest Greater [_Cutoff]
             AlphaToMask True
             
             Offset -1, -1
                 
             SetTexture [_MainTex] 
             {
                 Combine texture
                 Matrix [_Projector]
             } 
         }   
     }
 }

Download link: http://forum.unity3d.com/attachments/depthmaskprojector_847-unitypackage.8319/

thanks.