Seems Mac OS Sierra now doesn’t like running headless when you try to remote you get the black screen…this helps…
https://macminicolo.net/blog/files/build-a-dummy-dongle-for-a-headless-mac-mini.html
make your own if you have an adapter laying around or you cam buy online an HDMI one too
Maybe someone can find a better place for this info or maybe its been mentioned before.