You are missing the whole scenery, it's not that just something is black...
Verify that you see BOTH the "Addon Manager" AND the "Couatl powered plugins" under the "Addons" menu. If you are missing either menu (or both), the most probable cause it's a problem of your antivirus, that is mistakenly identifying this programs as threats. If this is the reason, it should be usually fixed in this way.
Please follow directions exactly:
- Uninstall the scenery. 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 the scenery with the Antivirus TURNED OFF in that way. Don't launch FSX yet.
- Configure the antivirus to exclude the following files from scanning:
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 that is asking permission to run the Addon Manager and the Couatl Scripting Engine. Reply YES to both questions.
- Check that you see BOTH the "Addon Manager" menu AND the "Couatl Powered plugins" menu under the FSX "Addons" menu. If you don't try to reboot Windows and launch FSX again.