Same here, load into the sim, have Couatl running. I click the button and wait approx. 45-60 sec. Then I looked at the Couatl window and it read.
"Addon GSX loaded
Starting system monitors
Traceback (most recent call last):
File ".\GSX\__init__.py", line 411, in onAppStart
AttributeError: 'module' object has no attribute 'emulateMenu_MSFS'
GSX SimStart
Loading aircraft.cfg from E:\Program Files (x86)\Microsoft.FlightSimulator_8wekyb3d8bbwe\Community\pmdg-aircraft-737\SimObjects\Airplanes\PMDG 737-700
Loading engines.cfg from E:\Program Files (x86)\Microsoft.FlightSimulator_8wekyb3d8bbwe\Community\pmdg-aircraft-737\SimObjects\Airplanes\PMDG 737-700
Loading flight_model.cfg from E:\Program Files (x86)\Microsoft.FlightSimulator_8wekyb3d8bbwe\Community\pmdg-aircraft-737\SimObjects\Airplanes\PMDG 737-700
Loading gameplay.cfg from E:\Program Files (x86)\Microsoft.FlightSimulator_8wekyb3d8bbwe\Community\pmdg-aircraft-737\SimObjects\Airplanes\PMDG 737-700
Loading systems.cfg from E:\Program Files (x86)\Microsoft.FlightSimulator_8wekyb3d8bbwe\Community\pmdg-aircraft-737\SimObjects\Airplanes\PMDG 737-700
this airplane has 15 exits
GSX flightLoaded C:\Users\grunt\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\MISSIONS\Custom\CustomFlight\CustomFlight.FLT
Airplane major/minor version: 737 700
aircraftDb.py provides aircraft data with priority 2 baseName = PMDG 737-700
Using aircraft data from aircraftDb.py
Specific .cfg file for N555LV not found in SimObjects\Airplanes\PMDG 737-700, using standard GSX.CFG file
Specific .cfg file for N555LV not found in C:\Users\grunt\AppData\Roaming\Virtuali/Airplanes\PMDG 737-700, using standard GSX.CFG file
User collision geometries reloaded
GSX variables RESET"