Update Splatmap Shader
If using Unity 2020.3 or later versions of the Universal or High Definition render pipelines, after importing TTM package, Splatmap shaders need to be recompiled:
Select Splatmap.shadergraph file in the Terrain To Mesh → Shaders → Splatmap folder and inside Inspector window click on the Copy Shader button:

After copying .shadergraph code, select Splatmap.shader file in the same directory and from the context menu choose the Amazing Assets → Terrain To Mesh → Generate Shader option:

Repeat steps 1 and 2 for the Splatmap (Holes) shader too.
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