made sure NOD32 and Malwarebytes are turned "off" during install
This is not nearly enough. As explained in all forums messages about antivirus, turning the antivirus off when installing might be required, but it's not enough, you should also do the following:
- BEFORE launching FSX, configure the antivirus to exclude the following files from scanning:
YourFSXFolder\bglmanx.dll
YourFSXFolder\fsdreamteam\Couatl\Couatl.exe
installed the vcredist_x64 and C++2013 as suggested in the trouble shooting section of the install guide
These are all 32 bit apps so, you should not install the x64 version, but the x86 version.
looked in the windows firewall for anything that might need to be added to the allow list, FSX is in there not sure what else needs to be.
Firewall doesn't have anything to do with *running* of executables, it can only affect downloads. If there was a problem with this, you would have seen a problem when installing, something like a failure to download.
installed all the vehicle updates I could find.
Vehicles updates don't have anything to do with *running* the modules. They are only needed to keep the vehicle library updated, without downloading the full GSX installer.
Be sure you use the CURRENT version of the GSX installer.
- DOWNLOAD AND INSTALL with the antivirus entirely OFF
- Uninstall GSX. Reply YES when asked if you want to remove the Addon Manager and the Couatl Engine. Reply YES to both questions.
- TURN OFF your antivirus. Don't just exit from its interface, but turn off the real time protection. Actual wording changes between products, however, it's the option to scan every file that gets open in real time, without user intervention.
- Reinstall GSX with the Antivirus TURNED OFF. Don't launch FSX yet.
- Configure the antivirus to exclude the following files from scanning:
YourFSXFolder\bglmanx.dll
YourFSXFolder\fsdreamteam\Couatl\couatl.exe
YourFSXFolder it's usually C:\Program Files\Microsoft Games\Microsoft Flight Simulator X, if you installed it in the default folder.
- Now you can turn the antivirus back on, and launch FSX.
- Check you are seeing BOTH the "Addon Manager" menu AND the "Couatl powered products" menu under the "Addons" menu