Wiki Silhouette Only Shader Not Working

Hi all,

I'm trying to just create an outline of a plane object (ideally a solid outline, with a transparent coloured centre), and found the silhouette only shader on the wiki (bottom shader found here) which would satisfy my needs temporarily.

When I apply this shader to my plane object, however, the object turns magenta (assuming because something is now not working in the shader).

Can anyone point me in the right direction?

Code (CSharp):

1. // Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'
2.  
3. Shader "Outlined/Silhouette Only" {
4.     Properties {
5.         _OutlineColor ("Outline Color", Color) = (0,0,0,1)
6.         _Outline ("Outline width", Range (0.0, 0.03)) = .005
7.     }
8. CGINCLUDE
9. #include "UnityCG.cginc"
10. struct appdata {
11.     float4 vertex : POSITION;
12.     float3 normal : NORMAL;
13. };
14. struct v2f {
15.     float4 pos : POSITION;
16.     float4 color : COLOR;
17. };
18. uniform float _Outline;
19. uniform float4 _OutlineColor;
20. v2f vert(appdata v) {
21.     // just make a copy of incoming vertex data but scaled according to normal direction
22.     v2f o;
23.     o.pos = UnityObjectToClipPos(v.vertex);
24.     float3 norm   = mul ((float3x3)UNITY_MATRIX_IT_MV, v.normal);
25.     float2 offset = TransformViewToProjection(norm.xy);
26.     o.pos.xy += offset * o.pos.z * _Outline;
27.     o.color = _OutlineColor;
28.     return o;
29. }
30. ENDCG
31.     SubShader {
32.         Tags { "Queue" = "Transparent" }
33.         Pass {
34.             Name "BASE"
35.             Cull Back
36.             Blend Zero One
37.             // uncomment this to hide inner details:
38.             //Offset -8, -8
39.             SetTexture [_OutlineColor] {
40.                 ConstantColor (0,0,0,0)
41.                 Combine constant
42.             }
43.         }
44.         // note that a vertex shader is specified here but its using the one above
45.         Pass {
46.             Name "OUTLINE"
47.             Tags { "LightMode" = "Always" }
48.             Cull Front
49.             // you can choose what kind of blending mode you want for the outline
50.             //Blend SrcAlpha OneMinusSrcAlpha // Normal
51.             //Blend One One // Additive
52.             Blend One OneMinusDstColor // Soft Additive
53.             //Blend DstColor Zero // Multiplicative
54.             //Blend DstColor SrcColor // 2x Multiplicative
55. CGPROGRAM
56. #pragma vertex vert
57. #pragma fragment frag
58. half4 frag(v2f i) :COLOR {
59.     return i.color;
60. }
61. ENDCG
62.         }
63.     }
64.     Fallback "Diffuse"
65. }