This happens if you got an mis-match between old and new Addon Manager versions, which shouldn't normally happen, since ENBR has an FSDT installer that always get the current version from the internet. A reason for this, might be your antivirus, which has mistakenly identified the program as a thread, blocking the download.
Try this:
- Uninstall the scenery. Reply YES to the question "Do you want to remove the Addon Manager?"
- Turn the Antivirus OFF.
- Reinstall the scenery, don't launch FS9 yet.
- Configure your antivirus to exclude the following file from scanning:
\YourFS9Folder\MODULES\bglman.dll
- Turn the antivirus back ON, launch FS9.
