Thank you for your assistance. I went through the uninstall and install procedure again, to get a fresh start for getting the files you requested. And now for some unknown reason, the program will load a flight plan. Unfortunately, it is not intuitively obvious, at least to me, how to use the program in my virtual flight. I will have to study the manual to see if I can get it to do what I want. My first impression is that it is far more complex than what I am looking for. I fly GA aircraft, mostly single engine Cessna's and Piper's, on short VFR flights of a few hundred miles. Even with the non-functioning ATC in P3D, I can get ATIS information by manually setting the frequency. But, until P3D offers a patch or new version to rectify the ATC problem, I can not communicate with the tower at a controlled airport. That was what I hoped PF3 would do for me. When I get time I will see what I can do about learning how to actually use the program, and during that process if I again have the failure to load a plan problem I'll follow up with your recommendations for what to send you.
I'm not asking you to explain how to use the program. I assume the manual does that, and when I have time I will study it. But, perhaps you could tell me from my description of what I am after whether PF3 is a potential solution. From what I see now it looks like it was designed for simulated commercial freight or airliner use.
Again, thank you for your prompt responses to my questions.
PF3 handles both IFR and VFR flights.
But to be honest - if you are not into reading long manuals and just want to jump into the cockpit, request takeoff clearance, fly along, then request landing at another airport and land there - then PF3 probably is not for you. You will be better off with the default ATC (which probably will be fixed in P3D V 4.3 - which is said to be quite close).
Please don't misunderstand. It's not meant condescending in any way. Everyone has his own way of simming and I also enjoyed those simple "plug and play" - VFR flights a lot before I found more fun in trying to do things more "professionally".
But if you want to dig a little deeper in ATC procedures then take a closer look at PF3 - and start with reading the manual...