Hello again & right from the start, thanks for your patience ... I have - partially - good news.

First let me answer your questions. Let's start with the prominent c:\ProgramData\Garmin\. Originally, it contained a \GTN Trainer Data\GTN\ with an empty GTN1nonvol and my first-trial \FPLN\ . Both appeared outdated, so I deleted \GTN Trainer Data\GTN\ and these two subdirs.

Now, after the update (first the trainer, then, following you, the RXP-software) that branch, c:\ProgramData\Garmin\, was extended (i.e. during the update process) to c:\ProgramData\Garmin\Trainers\Databases\ and c:\ProgramData\Garmin\Trainers\GTN\ The first received my flightplan-dir, i.e. became c:\ProgramData\Garmin\Trainers\Databases\FPLN\ (FPLN manually added), where I put 3 files: the waypoints and two flightplans, your user.wpt and KSLE_KSLE.gfp and an own LOWG_LOWG.gfp (Yepp, greetings from Austria!) re-saved from fms to gfp with (the newest) Little Navmap. The second extension now ends as c:\ProgramData\Garmin\Trainers\GTN\nonvol\, holding 4 EEPROM-files and 3 sys_nand-files. As mentioned, that FPLN-approach did not work. There are no other subdirs.

Now the good news. Following endless hours of trial, (re)search & error, I moved my FPLN-dir from

c:\ProgramData\Garmin\Trainers\Databases\FPLN\

to, guess  what, the non-default dir of my trainer-software:

j:\Programme\Fly\Garmin\Trainers\ProgramData\Databases\FPLN\

All without any env-vars. And it worked. Crazy(!) thing is, that this approach perfectly feeds X-Plane, but not the trainer standalone.

Finally, relating back to my "partially" good news running X-Plane: my GTN650 imports KSLE_KSLE.gfp, also successfully activates it (statusbar says ENR), and it  imports my LOWG_LOWG.gfp, but the latter activation ends with a TERM(inaton), some conflict, which I cannot resolve, even after reading manuals a/o consulting the internet.

Now the two most recent logs requested:

19/10/28 17:06:18.256 12100 -    ] # win.xpl version 2.5.20.2
19/10/28 17:06:18.256 12100 INFO ]

19/10/28 17:06:21.809 12100 -    ] # rxpGtnSim64.dll version 2.5.20.0
19/10/28 17:06:21.808 12100 INFO ]
19/10/28 17:06:59.173 12100 INFO ] GTN 650.1 - TRAINER 6620
19/10/28 18:23:30.018 12100 INFO ] GTN 650.1 - TRAINER 6620

Sorry couldn't do it shorter. Hope, I was sufficiently concise. Basically, from my view, the following questions remain:

1. Does this all make sense for you, should I keep my trainer-FPLN-dir?
2. Why can I not import with the trainer standalone?
3. How can I get my LOWG_LOWG.gfp correctly activated in X-Plane? (note: its fms-counterpart did the job in the GNS430/530 perfectly)

As always, thanks for reading and thinking ...

We're making progress indeed!

1 hour ago, Babbo said:

• Does this all make sense for you, should I keep my trainer-FPLN-dir?
• Why can I not import with the trainer standalone?

Please note: the trainer installer(s) save the installation location in specific registry keys.

For illustration with the Garmin GTN Trainer 6.50.1 registry keys:

With the registry key

"HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Garmin\Trainers"

Registry Values

"BinPath"="C:\\Program Files (x86)\\Garmin\\Trainers\\"
"DataPath"="C:\\ProgramData\\Garmin\\Trainers\\"
"DBDataPath"="C:\\ProgramData\\Garmin\\Trainers\\Databases\\"

Files Related to BinPath:
C:\Program Files (x86)\Garmin\Trainers\Packages\GTN\bin\GTN Simulator.exe
C:\Program Files (x86)\Garmin\Trainers\Packages\GTN\data\nonvol\sys_nand0

Files Related to DBDataPath:
C:\Program Data\Garmin\Trainers\Databases\safetaxi.bin

Files Related to DataPath:
C:\Program Data\Garmin\Trainers\Launcher\Manuals

 

The Launcher however, which runs the trainer standalone, manages its own additional 'session' data in the C:\ProgramData\ folder. This is normal therefore you'd use the folder identified with the installer set registry keys (in your J: drive) when running our product, unless you manually copy/move the folder someplace else, where it won't be referenced with the registry keys anymore, and for which we supply the environment variables as a convenient user oriented "override" path mechanism.

Now I don't know for the trainer standalone and you'd have to figure this one out with Garmin's support. It is possible some features which are made available and working with our product are not possible nor working with the trainer as-is... Our product is not just making a link between the simulator and the trainer, it goes way beyond this in simulating a real-world environment in the trainer and in enabling/disabling/controlling many other functions in the trainer (for example the OMI markers or the TX/RX flags...)

1 hour ago, Babbo said:

but the latter activation ends with a TERM(inaton), some conflict, which I cannot resolve, even after reading manuals a/o consulting the internet. How can I get my LOWG_LOWG.gfp correctly activated in X-Plane? (note: its fms-counterpart did the job in the GNS430/530 perfectly)

I'm certain this is something normal given how the trainer is working and managing flight plans.

@fppilot has written very helpful tutorials and information in our forums about all this. You might want to start searching in his posts?

I'm aware of that registry node. In my case, not to say consequently, i have 

BinPath    = J:\Programme\Fly\Garmin\Trainers\

DataPath   = J:\Programme\Fly\Garmin\Trainers\ProgramData\

DBDatapath = J:\Programme\Fly\Garmin\Trainers\ProgramData\Databases\

In the end, I don't have an idea why I also  have a c:\ProgramData dir and what it is for, why nonvol is targeted there, but FPLN must be in the trainer dir, and some things more - but, not surprisingly, I will keep everything as it is.

Additional thanks for the fppilot-link (even if can't follow your normal-argument).

16 hours ago, RXP said:

@fppilot has written very helpful tutorials and information in our forums about all this. You might want to start searching in his posts?

Babbo has sent me a PM about the flight plans and I have responded to him via PM.  I can replicate that here if desired, but it only speaks to the flight plan format issue, not to the other issues I see in this RXP - X-Plane topic.  I am not an X-Plane user.

Yes indeed, thanks again to fppilot for his help, I will study these links ...!

For now let's close that environment/path&registry-debate; even if I didn't fully check the reasoning why things (=paths) evolved as they did, but most importantly, locating FPLN at the trainer's side (please see above), I managed the import wanted.

Two other points still apply:

One question hasn't been answered at all: a flightplan, designed in a GTN or imported into a GTN and altered there in some way, can it be exported, e.g. in order to load it into Little Navmap?

Maybe it's a good idea to make my troublesome flightplan public. As noted, it can be imported into my GTN, but activation fails for whatever reason (TERM). Actually, this is a toy example, right, but its fms-equivalent was successfully used in a GNS430/530. Please find here that LOWG_LOWG.gfp from above - maybe someone has a sudden brainstorm!

FPN/RI:F:LOWG:F:N46521E015273:F:N46507E015246:F:N46493E015245:F:N46483E015261:F:N46491E015282:F:LOWG

(Note, this gfp was created by loading the fms into Little Navmap and using its export-save-as-GARMIN-function.)