License Manager Shows Zero Devices and does not Allow New Product Key

Issue
License Manager shows zero devices for both 'current' and 'maximum' number of devices. When entering a new product key, it gives the following message:
Retrieving the com class factory, error 80040154

Product Line
PME 7.x.x
ION Enterprise 6.0

Resolution
The IONSNG.dll file needs to be registered:
1. Open a command prompt; navigate to ..\ION Enterprise\System\Bin folder
2. Type regsvr32 ionsng.dll and press 'Enter' key