It's not a problem of the dll file, yours it's just fine. If it wasn't, you wouldn't see that error to begin with, because the module wouldn't be loaded.
I'm sorry, but there's no other solution than the one already posted above, try this for a better explanation:
Try to this, only this, and nothing else, in the exact precise order.
- Reboot Windows
- Remove all the bglmanx.dll files and the whole fsdreamteam\couatl folder manually. Empty the Recycle Bin as well
- Uninstall the scenery, reply YES to the question "Do you want to remove the Addon Manager?"
- Disable the Antivirus
- Reinstall the scenery
- Configure the Antivirus to exclude the FSX\bglmanx.dll file
- Run FSX, authorize both files, if asked.
- If FSX crashes once, try it again without doing anything else. If it still crashes, reboot Windows another time.
If it still doesn't work, try to download this fix from Microsoft:
- Download this update from Microsoft here:
http://www.microsoft.com/downloads/details.aspx?familyid=766a6af7-ec73-40ff-b072-9112bab119c2&displaylang=enUse the vcredist_x86.exe file.
Be sure you are NOT using FSX in "XP compatibility mode", if you are running Vista or Windows 7.