I'm sorry, I don't have any other solutions that all the one posted previously on this thread:
This error comes from a known FSX bug that, sometimes, a newly installed module that has just been trusted, will not run on the first try.
The solution is allow the module to run, and not worry if FSX doesn't start the first time. Just launch it another time and, if the error still comes out, reboot Windows and try again.
Another issue might be that if, for any reasons, your FSX wasn't closed properly when you were installing the scenery, some files weren't updated.
Try to do the following:
- Go to the FSX root folder, and manually remove the following files: bglmanx.dll, and all the bglmanx*.dat files (there should be 3 of them, remove all)
- Reinstall any scenery, and try again, as usual, allowing the module to run, even if it crashes and, eventually, reboot Windows before trying again.