Since "download nessusupdateplugins all-2.0.tar.gz" is technically a command instruction (likely meant for a Linux/Unix terminal) rather than a title of an existing document, I have drafted a Formal Technical Change Management Report.
Restart Service: While Nessus usually processes plugins automatically after an update, you may need to restart the service (service nessusd restart on Linux) if the plugins don't appear after a few minutes.
Before you can download the latest plugin set, you must identify your unique Nessus installation. Open your terminal or command prompt.
sudo ./nessusupdateplugins all-2.0.tar.gz
Download Archive: Use the challenge code and your activation code at the Tenable Offline Registration page to get your unique download link for the all-2.0.tar.gz file.