I just got a call from a macOS Sierra upgrader that Quicken (unknown version) no longer worked. I had the same problem with my several-years-old Quicken Essentials. Finding out about this kind of problem AFTER upgrading can be a major hassle, to say the least.
<http://roaringapps.com> can be a useful place to check for compatibility issues, but they don't seem to know about Quicken yet.
Quicken 2016 is the latest version, and it had better be Sierra compatible.
I was able to get off easy. I has able to open Quicken Essentials on an older Mac, and export its data in a compatible format. I then chose to jump off the Quicken merry-go-round altogether and switch to Banktivity (at the Mac App Store)
OmniOutliner Essentials and Pro 5.0.4
3 days ago