Just did a fresh installation and the problem still exist with "Couatl Scripting Engine has encountered an unrecoverable error...." Also the jetways are seen my FSDT KJFK and KFLL scenery but no terminal buildings. I also tried to revert to the previous version (v2.5.0.0) but during installation it updates to your updated version (v2.6.0.0). Please note I do not have any customize GSX .ini files for those sceneries.
I can only repeat and confirm the problem cannot possibly happen, unless you have another .INI file in use.
I'll repeat it again: the error message is very clear: the program is trying to load this object from your JFK .INI file
FSDT_SODE_JW_JBT_1_4_LOGO_HSBC
Do you see this name ANYWHERE in the .INI file for JFK you sent before ?
The only possible reason I can think of, is that you sent an .INI file taken from your Addon Manager folder, but GSX is not installed *there* and is not running from *there*
And not only that. We FIXED this problem so, regardless of which .INI file you use, the error won't appear anymore. The fix is already online on the Live Update so again, it just cannot happen with either .INI.