When custom shaders result in pink materials, particularly with newer Unity versions or render pipelines like URP, the underlying issue is often shader incompatibility. Older shader code may not adhere to modern rendering pipeline requirements or syntax. In such cases, the existing shader is effectively broken for the current environment, leading to the default pink error color.

A robust solution involves leveraging Shader Graph. This visual node-based editor allows for the creation of new shaders that are inherently compatible with your project render pipeline. For specific effects like dither transparency, Shader Graph provides a more streamlined and compatible approach than attempting to modify or debug outdated shader code. It is recommended to recreate the desired visual effects within Shader Graph to ensure proper rendering and compatibility.

1. Verify the active pipeline by checking Graphics Settings to confirm if URP or HDRP is in use.
2. Create a new Shader Graph asset by right-clicking in the Project Window and selecting Create > Shader Graph > URP > Lit Shader Graph.
3. Migrate the logic from your legacy shader into the nodes of the Shader Graph.
4. Assign the newly generated shader to your material.

Additional Tips

• If you must use code, ensure you use HLSL and include Core.hlsl from the URP package.
• Check the Inspector window with the pink shader selected to see specific compilation errors for debugging.
• Use the Shader Graph Blackboard to recreate properties like _MainTex or _Color so they appear in your material.