Toon/Lit Outline shaders broken in build by adding Screen Space - Camera Canvas

I'm using the Toon/Lit Outline shaders from the Standard Assets package and they work great until my latest build (Standalone Windows x86) where when I run the game I get the error :

"Shader 'Toon/Lit Outline': fallback shader 'Toon/Lit' not found WARNING: Shader Unsupported: 'Toon/Lit Outline' - Setting to default shader."

Through some messing around (and a lot of Googling) I've found the issue was caused by my adding a Canvas and setting it to Screen Space - Camera. It for some reason breaks the outline shaders, but anything using Toon/Lit shaders still works properly.

I should note the game still works perfectly in the editor, it's only on build where I get this error.

I've tried re-installing the shaders and adding them to the 'Project Settings > Graphics > Always Include Shaders' settings.

Does anyone with more knowledge in this area have any idea what could be going wrong? It seems to me if it works in the editor there's got to be a way to make it work in the build. I'd really rather not have to switch shaders as I really like the way these look.

Thanks in advance for any help.