ats Snow Suite - problem with DX11

I imported ats Snow Suite which works perfectly without DX11, but when i turn on DX11 option everything change color to pink except trees and grass, i have this error in shader:

incorrect number of arguments to numeric-type constructor

this lane:

 o.Gloss = half(snowAmount*(1-snowtex.rgb));

and this is all shader:

 Shader "snowShader Bumped Diffuse" {
 Properties {
     _Color ("Main Color", Color) = (1,1,1,1)
     _MainTex ("Base (RGB)", 2D) = "white" {}
     _BumpMap ("Normalmap", 2D) = "bump" {}
 }
 
 SubShader {
     Tags { "RenderType"="Opaque" }
     LOD 300
 
 CGPROGRAM
 #pragma surface surf Lambert vertex:snow
 #pragma exclude_renderers flash
 //#pragma target 3.0
 
 
 sampler2D _MainTex;
 sampler2D _SnowTex;
 sampler2D _BumpMap;
 fixed4 _Color;
 
 float _snowShininess;
 float _SnowAmount;
 float _SnowStartHeight;
 sampler2D _SnowTexture;
 
 struct Input {
     float2 uv_MainTex;
     float2 uv_BumpMap;
     fixed4 color : COLOR;
     float3 worldPos;
     fixed3 MyWorldNormal;
 };
 
 
 void snow (inout appdata_full v, out Input o) {    
     o.MyWorldNormal = normalize(mul((float3x3)_Object2World, v.normal));
 }
 
 
 void surf (Input IN, inout SurfaceOutput o) {
 
     fixed4 col = tex2D(_MainTex, IN.uv_MainTex) * _Color;
     fixed4 snow = tex2D(_SnowTex, IN.uv_MainTex);
     o.Alpha = col.a;
     o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
     
     // get snow texture // distribution might be stored in alpha
     half4 snowtex = tex2D( _SnowTexture, IN.uv_MainTex);
     
     // clamp(IN.MyWorldNormal.y + 0.6, 0, 1) = allows snow even on orthogonal surfaces // (1-col.b) = take the blue channel to get some kind of heightmap
     float snowAmount = (_SnowAmount * (clamp(IN.MyWorldNormal.y + 0.6, 0, 1)) * (1-col.b) *.8 + clamp(o.Normal.y, 0, 1) * _SnowAmount * .25);
 
     // clamp snow to _SnowStartHeight
     snowAmount = snowAmount * clamp((IN.worldPos.y - _SnowStartHeight)*.0125, 0, 1);
     
     // sharpen snow mask
     snowAmount = clamp(pow(snowAmount,6)*256, 0, 1);
     
     o.Alpha = 0.0;    
 
     // mix 
     o.Albedo = col.rgb * (1-snowAmount) + snowtex.rgb*snowAmount;
     o.Gloss = half(snowAmount*(1-snowtex.rgb));
     o.Specular = _snowShininess;
     
     // smooth normal
     o.Normal = normalize(lerp(o.Normal, float3(0,0,1), snowAmount*.50));
     
 }
 ENDCG  
 }
 
 FallBack "Diffuse"
 }
 

what's wrong ? ;/