I have just started on FG after decades doing that "other simulator program" on Windows machines. I have 3 iMac computers with Sierra or High Sierra Mac OS X, linked by local network. These are for the cockpit center view of instrument panel and forward scenery on the master iMac. Two slave computers that are for scenery out left and right of center are fine. Good frame rates, no big errors but occaisional FG program crashes on the master iMac, a different problem I use the latest FG version for Mac OS X in all.
I am running the starter plane, the Cessna 172 on normal beginnings, Long Beach runway, noon, fair weather, no wind. Flying looks pretty good over all for such early results.
The 4th iMac, an "El Capitan" Mac OS X version, also runs fine but for just the instruments. Where it looks bad is not all instruments seem active. The engine RPM gauge works okay. The bank indicator liquid ball works, but not the little airplane above it. Gyrocompass, altimeter, and attitude don't work, but used to. The airspeed never moves off zero, most annoying. Other smaller dials like temps and fuel also never move of zero.
This situation of just the partial instruments active was duplicated by a Windows 10 laptop running the latest Windows version of FG.
Any idea how to get all the instruments to be active? Thank you, Gregg