Look for a button or link labeled or Manage Products .
link. This unlinks the code from the previous machine and makes it available for a new registration. 2. Generate a New Challenge Code
Enter your newly generated and your Activation Code .
A unique hardware string generated by your specific Nessus installation. nessus offline activation license already in use
Confirm the reset. Once complete, the code will show as available and can be used for a new registration.
Run the following command on the machine giving the error:
Is this scanner running on a or physical hardware? Look for a button or link labeled or Manage Products
Restart the Nessus daemon to apply all changes:
Finalise the activation on the offline system by running the registration command:
You wiped the OS (Windows/Linux) and reinstalled Nessus. The hostname or network configuration changed slightly. The new Challenge Code does not match the old one. Tenable rejects the attempt because your license key is already "Checked out" to the previous OS install. Confirm the reset
I can provide specific terminal commands or alternative strategies based on your setup. Share public link
This comprehensive guide will walk you through why this error happens and how to resolve it safely using Tenable Community Portal resets, command-line overrides, or proper migration workflows. Why This Error Happens
The offline activation process relies on a challenge-response mechanism using two key components: