Hi,
Just saw that yamaha released a working fw driver for macos sierra (mr816 is on the list).
Steinberg has yet to update it’s site.
Anyone want to give it a try?
http://download.yamaha.com/search/detail/?site=europe.yamaha.com&language=en&category_id1=16244&category_id2=16268&product_id=592444&asset_file_language=EN&asset_id=68394