There's a problem in your FSX Steam installation (leftover from FSX), that we were able to handle in the latest GSX and Stand-Alone Addon Manager installer, but the scenery installer haven't been updated yet.
The source of the problem, is that you had FSX Steam edition initially installed alongside FSX, so it installed using the FSX:SE-specific registry keys, but then you removed FSX and reinstalled FSX:SE into stand-alone mode, so it's now using the FSX registry keys.
Unfortunately, probably due to a bug in the FSX:Steam uninstaller, the FSX:SE-specific registry keys are still there, so this makes the installer assuming is still installed alongside FSX when it's not, so it gives you an error because the %APPDATA%\Microsoft\FSX-SE folder is not there anymore, and it's not used when FSX:SE is installed stand-alone.
As I've said, our recent installers are able to deal with this, but sceneries installers must be updated (we are waiting to exit from Beta status of the latest Couatl program), so you can probably fix it this way:
- Open the REGEDIT program
- Go to the HKEY_CURRENT_USER\Software\Microsoft\Microsoft Games folder remove this sub-folder:
Flight Simulator - Steam Edition
- You should also see the regular "Flight Simulator" folder. DO NOT REMOVE THIS!
- Launch all the FSDT installers that gave you the error.
