Did you recently upgrade(?!?) to Win10? Like I mentioned, Win10 will give problems where there were none before with programs, other than Windows stuff, in "that" location. Some Windows updates to the other versions will too. It's not FSX, per se, it's that the UAC stuff, even turned off in the Control panel, will still act like it's on, whether you like it or not. I think the error message said that it was trying to copy a file into FSX. Being in "that" location, Windows may be preventing it due to an update to your Windows version, or a change to Win10, whether you permit it specifically or not.
Now, I may be way off on this, but I read several forums, and there are tons of posts about this. I can't do this, I can't add that add-on, thus-and-such a program suddenly doesn't work, etc etc. The common wisdom that I can find says to stay away from that default location.
It may also be a problem with the version and/or location of the .dll mentioned in the error message. Try Googleing (is that a word??) the "(DLL Mentioned) in FSX" and see what pops up. I think it was bglmanx.dll, right? So try Googleing "bglmanx.dll fsx" (no quotes). There may be something about either version or location of the file you have as opposed to the file it is looking for.
I am sure the great Virtuali will stick his head in here eventually and solve your problem in 5 simple words. He does that all the time, but right now is probably enjoying a nice Thanksgiving break. I'm sure he'll be back in day or so.
Not super helpful, I know, but it's the best I can do for you. Sorry...
Pat☺
