The same error occurs for me, I'm getting the error in the PMDG 777, the FSL A320X, the PMDG 747 and 737.
This is the panic log I've quickly created:
couatl v3.2 (build 3852)
panic log started on Fri Oct 27 20:32:18 2017
problem raised by addon <unknown>
Traceback (most recent call last):
File "couatl\common\fsm.py", line 73, in executeDoFuncToCompletion
File ".\GSX\assistanceServices\__init__.py", line 326, in do
File "couatl\common\criticalsection.py", line 23, in _synchronized
File ".\GSX\assistanceServices\__init__.py", line 144, in requestVehicles
File ".\GSX\__init__.py", line 907, in prepareGate
File ".\GSX\assistanceServices\__init__.py", line 2018, in setGate
File ".\GSX\assistanceServices\baseAssistanceVehicle.py", line 145, in setGate
File ".\GSX\assistanceServices\baggageLoader.py", line 80, in getSimObjectModel
File ".\GSX\assistanceServices\conveyorBelt.py", line 57, in __init__
IndexError: list index out of range
{'Airport': 'KVPS', 'Requested assistance services at': 'Gate G 3', 'User Pos': (30.495116284417936, -86.54904915395315, 30.8998 m, 4.38282 m, 273.0692431903666)}
I've completely reinstalled GSX and all FSDT/Couatl airports, uninstalled addon manager, deleted all Addon-Manager/Virtuali folders from Programs(x86), AppData Roaming and ProgramData directories.
I then reinstalled GSX, my airports and on top of it Addon Manager again, all files downloaded freshly from the website. I've excluded all mentioned directories from my antivirus and also switched it off for testing/installing.
I did this twice today, as I can't really fly, sometimes it works for a time and then it crashed P3D. Also Live Update doesn't change a thing.