P3D V4 Fix
Check the dll.xml file, which is found here in win 10
C:\Users\username\AppData\Roaming\Lockheed Martin\Prepar3D v4 for the following entry.
<Launch.Addon>
<Name>Carenavigraph</Name>
<Disabled>False</Disabled>
<Path>.\Carenavigraph.dll</Path>
</Launch.Addon>
It should look like this
<Launch.Addon>
<Name>Carenavigraph</Name>
<Disabled>False</Disabled>
<Path>.\Carenavigraphx64.dll</Path>
</Launch.Addon>
For some reason the x64 is missing off of the end of the .dll file name.
Work for the Hawker 850 and King Air 350i