System.InvalidOperationException: Shader Compilation Failed

I’m porting a number of shaders from my current UWP game to Android. I followed the instructions here: http://www.monogame.net/documentation/?page=Custom_Effects.

A simple WxVxP + single texture shader runs fine, but a more complex diffuse + normals + specular maps shader gives “System.InvalidOperationException: Shader Compilation Failed” at runtime.

What exactly is this exception (the shader compiled successfully) and is there a way to see more details about it?

Tested this with Microsoft’s Android emulator.