On your offline scanner, apply the license using the command line:
/opt/nessus/sbin/nessuscli fetch --register-offline nessus.license
The error occurs because Tenable's license server believes the code is currently active on another machine. Common causes include: nessus offline activation license already in use
With a reset license and a new Challenge Code, you can now generate the license file. Go to the . Enter your Activation Code (the one you just reset). Paste your New Challenge Code . Click Submit and download the nessus.license file. Copy this file to your offline machine. Step 4: Apply the License and Plugins
Here is a comprehensive guide on why this happens and how to fix it. Why You See the "License Already in Use" Error On your offline scanner, apply the license using
After the license is accepted, remember that you will also need to manually download and install the latest plugin set ( all-2.0.tar.gz ) since the machine has no internet access to pull them automatically. Pro-Tips for Avoiding Future License Issues
💡 Tenable limits how many times you can reset a code manually (usually once every 24 hours). If you have exceeded this limit, you must contact Tenable Support to request a manual reset. Step 2: Generate a New Challenge Code Enter your Activation Code (the one you just reset)
Because offline licenses are manually tied to a unique hardware fingerprint, any change in your system configuration or a previous failed installation can block a new activation attempt.
Open an Administrator Command Prompt and run: C:\Program Files\Tenable\Nessus\nessuscli.exe fetch --challenge Keep this new string of characters handy for the next step. Step 3: Perform the Offline Activation Again