I think I have this right.
Opened AHIII and it ran fine.  TrackIR ran fine.  Switched sides in whatever the MA is this night, and it was fine.  Took off in a 202, it was fine, but I didn't like my rear view.  So I alt-tabbed out of AHIII, raised the TrackIR program, switched off the True View box.  AHIII had disappeared; Task Manager couldn't find it, it didn't appear in the Win10 bar on the bottom of the screen, and yet, when I tried to start it again, it refused to start.  Have to reboot my computer and do it all over again.
In fact, this happens whenever I alt-tab out of AHIII, regardless of what I do next.  Wouldn't mind it so much if I could just start AHIII up again, but I have to reboot the whole computer, and I am tired of doing this.
- oldman