This error is caused by an invalid SimConnect client installation, and Active Sky cannot find the proper SimConnect module(s) in order to communicate with FSX properly.

Here are the solutions:

Reinstalling the FSX update(s) (recommended procedure)

The first step in attempting to repair your SimConnect installation is to uninstall/reinstall FSX’s SP1 or SP2 update.  Removal is done in add/remove programs, making sure to check the "Show updates" box to see the SP1, SP2 or Acceleration/SP2 update entry (if XP) or choosing the "View installed updates" option in (Vista/7).

The majority of potential installation issues will be solved with this method.

Manual deletion and reinstallation (if recommended reinstall procedure does not fix the problem)

Warning!  Modifying your GAC or Windows SxS files can cause improper configuration of the SimConnect modules, and is not recommended for most users.  Complete re-installation of FSX may be required.

If further problems are experienced, the actual SimConnect installation may be damaged/corrupt and the normal reinstall procedure may not work to correct the situation.  If the described reinstall does not work, please follow these instructions to force a manual reinstallation:

If you have FSX Deluxe:

• Install the SDK from the DVD (if not already installed).
• Update to SP1A or SP2 SDK from www.fsinsider.com (if not already updated).
• You will need the simconnect.msi file located in your SDK folder's Core Utilities\SimConnect SDK\lib subfolder.
• Run this .msi file (double click) and the appropriate SimConnect files will be installed.
• A complete uninstall and reinstall of FSX may be required if none of these methods work.  You can also contact Microsoft Technical Support for your FSX product.

If you do not have FSX Deluxe:

• Uninstall/remove the SP1, SP2 or Acceleration update(s) as described above in the recommended procedure
• Using Windows Explorer, locate the folder: C:\Windows\winsxs\ for XP or C:\Windows\assembies(your Windows folder may be different if you chose to install it into another location.  C:\Windows is the normal default)
• In this folder will be one or more entries for x86_microsoft.flightsimulator.simconnect.  Backup these entries!  Copy and paste it to another location i.e. C:\Backup
• Delete all version entries v 10.0.61242 AND LATER by highlighting it and pressing the DELETE key on your keyboard (confirm YES to delete) - DO NOT DELETE ANY OTHER ENTRIES!!!  DO NOT DELETE v 10.0.60905!
• Reinstall the FSX update(s) in order as desired
• If the SimConnect files were not properly installed (which can occur in some situations), you may need to restore your backed-up entries
• A complete uninstall and reinstall of FSX may be required if none of these methods work.  You can also contact Microsoft Technical Support for your FSX product.