I wrote a quick fix that just ignores fuel lines and structs in stock aero. Its not a great sollution but I really needed this mod to work, at least partially :)
If someone is interested, download is here
[URL]https://github.com/martinjaros/KSPTrajectories/releases/download/v1.4.4-quickfix/Trajectories.zip[/URL]
EDIT: it actually ignores any part that generated the exception, it seems there are more[URL="https://github.com/martinjaros/KSPTrajectories/releases/download/v1.4.4-quickfix/Trajectories.zip"] [/URL]