Operator '*' cannot be used with a left hand side .......

Hello

When I switch platform to android(trial version) is show me error in the console.

function aniSprite (columnSize, rowSize, colFrameStart, rowFrameStart, totalFrames, framesPerSecond) { var index : int = Time.time * framesPerSecond;
index = index % totalFrames;

 var size = Vector2 ( 1.0 / columnSize, 1.0 / rowSize);                                        
 
 var u = index % columnSize;                                                                    
 var v = index / columnSize;                                                                    
 
 var offset = Vector2 ((u + colFrameStart) * size.x,(1.0 - size.y) - (v + rowFrameStart) * size.y); 
 
 renderer.material.mainTextureOffset = offset;                                                    
 renderer.material.mainTextureScale  = size;                                                        
 
 renderer.material.SetTextureOffset ("_MainTex", offset);                                    
 renderer.material.SetTextureScale  ("_MainTex", size);                                    

}