A word of thanks… I recently read on the forum that if version 10 is installed on a separate partition under its compatible Mac OS, FMP 10 will operate when the computer is booted from High Sierra. I gave it try… sure enough, everything works just fine. Wow.
For years I’ve been working out of two offices: Snow Leopard for FMP 10, and whatever the latest OSX for everything else. Big hassle, especially since Snow Leopard's Safari is incompatible with today's websites.
I use FMP for a genealogical project recording data from Italian civil records, 1820-1910. It’s an extensive and detailed db, searchable, and printing various forms to document and verify information when discrepancies exist (often).
*I am a single user and my db has not been tested under local or internet conditions, so I don’t know how this system arrangement fares in a networked scenario. But works perfectly for my humble needs.
Big thanks to the community!