Uniform variable fails on the android

Hello,

I set a shader's global variable in my c# code and use this variable in the shader. It works correctly on my laptop, but when I load it to my android phone, the shader doesn't work( it just draws default color for the object). I use Unity 4.3.0, and build apk by OpenGL ES 3.0 and Android 4.3. My phone runs Android 5.0.

This is the c# code:

 void OnPreRender()
 {
     Shader.SetGlobalInt("OFFSETX", mOffsetX);        
     
 } 

This is the glsl:

Shader "GLSL Test"{ SubShader { Pass { GLSLPROGRAM

      varying vec4 position; 
      uniform int OFFSETX = 0;
      uniform int OFFSETY = 0; 
      #ifdef VERTEX    
     void main()
      {       
      }   
      #endif 
     
 
      #ifdef FRAGMENT         
      void main()
      {
         if( fract((gl_FragCoord.x+OFFSETX)/16.0f)< 0.0625)      
         {
         
             gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);
      
         }
         else
         {
   
             discard;
         }
         
      }
 
      #endif 
        ENDGLSL 
   }

} }

Thank you so much in advance!!