Custom shader worked in 2019 but not in 2020.1.17f

I don't know much about shaders but I wrote a custom one. I got it to work in Unity 2019 but it doesn't work in Unity 2020.1.17.

This is what it looks like now


This is what it is supposed to look like


This is the code for the shader

Code (CSharp):

1. Shader "Custom/DoubleSidedDecal"
2. {
3.  
4.     Properties{
5.         _Color("Main Color", Color) = (1,1,1,1)
6.         _MainTex("Base (RGB)", 2D) = "white" {}
7.      
8.         _DecalColor("Decal Color", Color) = (1,1,1,1)
9.         _DecalTex("Decal (RGBA)", 2D) = "black" {}
10.         _Illum("Illumin (A)", 2D) = "white" {}
11.         _Emission("Emission (Lightmapper)", Float) = 1.0
12.     }
13.  
14.         SubShader{
15.             Tags {"RenderType" = "Transparent" "Queue" = "Transparent"}//Tags { "RenderType" = "Opaque" }
16.             LOD 100
17.         Cull Off
18.              ZWrite Off
19.                  Blend SrcAlpha OneMinusSrcAlpha
20.  
21.         CGPROGRAM
22.         #pragma surface surf Lambert alpha
23.  
24.         sampler2D _MainTex;
25.         sampler2D _DecalTex;
26.         sampler2D _Illum;
27.         fixed4 _Color;
28.         fixed4 _DecalColor;
29.         fixed _Emission;
30.  
31.         struct Input {
32.             float2 uv_MainTex;
33.             float2 uv_DecalTex;
34.             float2 uv_Illum;
35.         };
36.  
37.         void surf(Input IN, inout SurfaceOutput o) {
38.             fixed4 c = tex2D(_MainTex, IN.uv_MainTex);
39.             half4 decal = tex2D(_DecalTex, IN.uv_DecalTex);
40.             decal *= _DecalColor;
41.             c *= _Color;
42.             c.rgb = lerp(c.rgb, decal.rgb, decal.a);
43.  
44.             o.Albedo = c.rgb;
45.             o.Emission = c.rgb * tex2D(_Illum, IN.uv_Illum).a;
46. #if defined (UNITY_PASS_META)
47.             o.Emission *= _Emission.rrr;
48. #endif
49.             o.Alpha = c.a;
50.         }
51.         ENDCG
52.     }
53.  
54.         Fallback "Legacy Shaders/Diffuse"
55. }
56.