Two NLAirSyncRedirect filters appear in the IIS admin after upgrading from NLES 4.5.1 to NLES 4.5.2.
Open the IIS admin, right click on Default Website, click Properties, then click the ISAPI Filters tab.
Two NLAirSyncRedirect filters appear.
This happens because the filter is not removed when NLES 4.5.1 is uninstalled and is added again when 4.5.2 is installed. This will not have an adverse affect and can remain this way until a subsequent upgrade, after which a single filter will remain.
This issue is resolved in NotifyLink Enterprise Server version 4.6.0.