Oddi, that's just a warning, not an error, meaning that the "unknown" option hlsl_write is ignored but the rest was imported as expected.

I've been told earlier by MAME devs that this option should not be user-visible for now, so it's marked as ignored in the configuration template (data/opt/MAME/template.xml).

A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]