I've owned this plane since it came out. I really like the option of switching to the G600. I just had to reinstall FSX/Acceleration on my machine, the old one was clogged with gremlins. Problem is, after doing a fresh reinstall of the Seminole right from my account in Carenado the G600 option does nothing.  I looked at the config file and couldn't see anything obviously wrong. Any guesses?  I might add that last week it worked fine, before the reinstall. Same machine same settings so I won't bore you with my specs.

Tommy did you ever get the G600 to work again in the Seminole?

I've just had a similar problem after a failed beta install of FSX:SE. After the failed beta install (locked font file) I returned to the latest Steam version of FSX and things haven't been the same since. Not only does the native G600 cease to work but the Flight1 G500/600 has failed too. I did find that switching the aircraft battery on and off helped to start the instruments (GTN750 and G500/600) but the G500/600 does not update. I've uninstalled the gauges and re-installed likewise with the aircraft (Seminole) but still the error persists.

This is also true with the Chieftain, that has similar gauges.