I'm not sure why you spend so much time explaining that your program isn't the problem when it clearly is. YS02400 has given you the exact cause.
No, he hasn't, that wasn't the cause and even if that change fixed it, it fixed it in the wrong way, because with that method all liveries would get the same generic crew. The whole point of having to create a new local model folder for a livery (when there isn't already one), is to have airline-specific Crew.
The lines in the model.cfg were always CORRECT as they were, the real cause is something else entirely.
Have you tried downloading any livery available, enabling GSX Seated Passengers, and then loaded into the sim? Everyone else has exactly the same issues because it seems you haven't attempted this at all except with the default livery which has all its dependencies inside it.
I tried it, but I haven't tried all liveries, and this problem happens only to liveries that didn't had already a custom model folder, requiring the FSDT Installer to create a new local folder and copy the original exterior model from it. I finally understood the real cause, it's because the A380 is only one using this method to include shared behaviors:
<include RelativeFile="xxxx">
instead of the more commonly found:
<includeBase Path="xxxx">
The second form is usually more flexible for liveries, since it can use both relative and absolute path, even outside the own package folder, while the first form can only refer to a path relative to the package the file is located, making liveries less "movable" this way, since many liveries are usually located in a different package entirely,
I'M
NOT saying FBW made a mistake doing this!!! The first syntax is perfectly valid, just that it doesn't play well with the fact the FSDT installer needs to copy the file to a new folder in another package, so we just have to change the lines automatically, from this:
<Include RelativeFile="behaviour\engines.xml" />
<Include RelativeFile="behaviour\door_animations.xml" />
to this:
<Include RelativeFile="..\..\FlyByWire_A380_842\model\behaviour\engines.xml" />
<Include RelativeFile="..\..\FlyByWire_A380_842\model\behaviour\door_animations.xml" />
THIS is the REAL fix and, of course, will appear in the installer very quickly.