"Too many interpolators used" shader error

this is an shader error.
"Shader error in 'IBL/IBL_Specular': Too many interpolators used (maybe you want #pragma target 3.0?) " here is my shader code parts

 struct Input   
 {
  
  fixed3 Color1;    <= problem line if added  
  fixed3 Color2;    <= problem line if added  
 
  float4 texcoord;  
  float3 worldNormal;  
  float3 viewDir;  
  float4 worldP;  
  INTERNAL_DATA  
 };  
 
  \#pragma glsl  
  \#pragma target 3.0  
  \#pragma exclude_renderers gles d3d11_9x flash  
  \#pragma surface TempSurf TempDirect vertex:Temp_Vert fullforwardshadows alphatest:_Cutoff  
 
 void TempSurf (Input IN, inout TempOutput OUT)   
 {  
 half4 diff = tex2D( _MainTex, uv_diff ) * baseColor;  
 OUT.Albedo = diff.rgb * IN.Color1 * IN.Color2;  
 }  

#pragma target 3.0 is declared and even if it's SM2.0, i think i can use 8 unit of float4's from vertex shader => fragment shader. Ofcourse other Input variables(texcoord,worldNormal...) are used.
what's wrong with that?