proofresistant
It had been years since I had looked at a Garmin application in such depth. Due to its complexity and lack of support, I abandoned Garmin more than 10 years ago and it appears that nothing has changed in this regard. My last visit to the shop, when I was still unsure about my choice ...

FrankB

Mapsource? Yes, sure I still know that program too of course.
Mapsource is strict when it comes to the gpx core, but does not read the extensions.
As so ShapingPoint did not exist at the time. This came later in the trp extension.
Color was also not available. This is now offered in the ...

proofresistant
Very interesting new information.
XML Notepad does not show errors as there are none.
This GPX file is valid and imports into Basecamp.

Why does it work?
Look at the GPX header.
creator=" Tread 2 "
And the new xml namespace
xmlns:trp="http://www.garmin.com/xmlschemas ...

Well, the situation is this.
I don't have a motorcycle and haven't had a Garmin (cycle) GPS for over +10 years.
I sometimes still use Basecamp as a tool to quickly check whether a GPX file is valid.
This is also very effective for the many Garmin extensions with schematics.
Basecamp imports the ...

proofresistant

Microsoft XML Notepad is quite unique in that, in addition to the GPX core, it also checks the Garmin extensions based on their schema.
https://microsoft.github.io/XmlNotepad/

Validation using this tool is therefore recommended by Topografix.
https://www.topografix.com/gpx ...