If you load the changed plan from the NGX folder, it won't let you save it again unless you change it again.

There is no need to save it. When you retrieve a saved route, the FMC does essentially a copy/paste from the NGX folder. So there is still a copy of the route in the NGX folder.

 

 

The FMC doesn't clear the "confirm" LSK.

 

My first guess is that it cannot over write a file because of access rights, if you have FSX installed in the Programs (86) location then UAC can be a pain.  If you haven't already, assign admin rights to FSX and folders. Make sure the flightplans folder for NGX is accessible.  The confirm message will normally go away, in fact I've never seen what you describe in years of use.  If the guessing fails, please submit a ticket to PMDG Product Support.

I have full administrator rights to the NGX folder and the FMC creates new flight plans. It is only revisions to existing flight plans that don't happen the way I expect. I have had the PMDG B747-400x for a couple of years and recently purchased the MD11 aircraft. There doesn't seem to be a flight plan problem with any of those airplanes. Only the B737-NGX exhibits this characteristic. I haven't exhausted all the options for this condition and plan to continue testing to determine if there is something in the way I handle flight plans that makes this unique.

 

I have several other aircraft that use FMC's and they do what I expect. But different software manufacturers use slightly different protocols so the procedures are different.

 

 

Only the B737-NGX exhibits this characteristic. I haven't exhausted all the options for this condition and plan to continue testing to determine if there is something in the way I handle flight plans that makes this unique.

 

Having admin right to the folders and running the program as an admin are separate issues of operation. Ensure that you're running FSX as an admin as well.

 

Also, while I'm guessing that your user name is your real name, signatures are required in the message body.