Hi Chris:
This could prove challenging to troubleshoot if you have already tried installing those (2) different versions of the FSX SDK:
http://www.fsdeveloper.com/forum/th...ration-editor-will-not-load-xml-files.435142/
I suggest that you forego tinkering further with the (2) other installed FSX SDK versions for now, and
instead install the Lockheed Martin P3Dv1.4x version of the FSX / ESP / P3D SDK.
https://www.prepar3d.com/support/sdk/
"
Prepar3D v1.4 SDK
The Prepar3D® SDK is available as a free download to anyone looking to get into developing add-ons or content for Prepar3D®.
The Prepar3D SDK 1.4.4747.0 (Prepar3D SDK Release 1.4) is directly compatible with Prepar3D 1.4.4747.0 (Prepar3D Release 1.4). The SimConnect.lib and LockheedMartin.Prepar3D.SimConnect.dll provided in the SDK cannot be used to connect to FSX, ESP or any previous release of Prepar3D.
The SimConnect server in the Prepar3D application is backwards compatible with the SimConnect.dll’s of FSX and ESP and the ESP SimConnect server is backwards compatible with the SimConnect.dll’s of FSX. This means that if you are trying to develop an add-on that will work with FSX, ESP, and Prepar3D, you will need to use a version of the SimConnect SDK that works with FSX.
Click
here to open the online SDK documentation (1.4.4747.0).
Click
here to download the Prepar3D SDK with tools and the SDK Learning Center documentation.
The SDK documentation is now accessible via the new SDK Learning Center application. This application is installed in your Start Menu when you install the SDK. It can also be found in the SDK installation directory in \LC\LearningCenter.exe."
NOTE: The Prepar3D SDK 1.4.4747.0 (Prepar3D SDK Release 1.4) is essentially identical to the (2) other FSX SDKs you already installed, except that it automatically runs the SDK path configuration utility and writes SDK-related Windows system variables to the proper parts of the Windows Registry, so that when any of the SDK tools (and all other 3rd party FS utilities I've tested) are run, they successfully "find" the correct SDK file / folder paths
without any problem.
Let me know if you have an ongoing problem after installing the above P3Dv1.4x version of the (FSX) SDK.
PS: Unless you are concerned about severely limited hard disk drive storage space, I would
not recommend attempting to manually remove and re-install the other (2) versions of the FSX SDK, as they only occupy about 435 MB of space for each folder chain.
But if you are insistent on delving into those complexities, you may find "some" help here:
http://www.fsdeveloper.com/forum/forums/sdk-installation.111/
GaryGB