(version 12.16.9.574) and activate it using their original version 9 serial number. Move to Nitro Pro 13 or 14
To continue using your license, Nitro recommends moving to a newer version that is compatible with current activation systems. Current Activation Procedure Nitro Pro 9 Activation
For a user holding a valid license, the activation workflow is designed to be seamless but strictly controlled. (version 12
Even as a legacy tool, Pro 9 offers robust capabilities that remain relevant today: Nitro Pro 9 Activation