When you open Local Security Policy for a Windows 10 PC, you get this error:
Namespace Microsoft.Policies.Sensors.WindowsLocation is already defined as the target namespace for another file in the store
This is because the LocationProviderADM.admx admin template was renamed to Microsoft-Windows-Geolocation-WLPAdm.admx in Windows 10, and after updating from a previous version of Windows (either updating these files in a central store, or if you upgraded from Windows 8.1 and have these files locally), there are two admx files containing the same settings; Hence the namespace is already defined in the first file that was read into the local security policy.
To fix this, you can either just ignore the error, or:
Delete the LocationProviderADM.admx and LocationProviderADM.adml from the central store (or local PC if the namespace already defined warning is in Local Security Policy only)
Rename Microsoft-Windows-Geolocation-WLPAdm.admx to LocationProviderADM.admx
Rename Microsoft-Windows-Geolocation-WLPAdm.adml to LocationProviderADM.adml