This is the honest truth. While I love Nitro Pro 9 for its speed and lack of subscription, there are serious risks to using it today.
While Nitro Pro 9 was a powerhouse in its time, it is important to note that it was designed for Windows 7 and 8. If you are running Windows 10 or 11, you may encounter stability issues or "Side-by-Side" configuration errors. Furthermore, legacy versions no longer receive security patches. If you find that activation is consistently failing despite having a valid key, it may be time to consider reaching out to Nitro support for an upgrade path to the latest version, which offers significantly better integration with cloud services and modern operating systems.