Nessus Offline Activation License Already In Use
If you change the network interface card (NIC), hostname, or MAC address of an offline server, Nessus may generate a new challenge code. Tenable views this as a completely new machine trying to steal an active license.
A link to download your Nessus plugin archive ( all-2.0.tar.gz ).
provides the step-by-step requirements for challenge codes and license application. For transferring licenses between hosts, refer to the License Transfer instructions to avoid seat conflicts. Tenable Knowledge Base explains common reasons for the 'Code in Use' error. Tenable Discussions
Tenable’s Nessus is the gold standard for vulnerability assessment, but for systems in air-gapped or highly restricted environments, the offline activation process can be a source of frustration. One of the most common and confusing errors encountered during this process is: nessus offline activation license already in use
Although less likely to cause a "license in use" message, an incorrectly set system date and time on your offline server can cause license validation failures. Certificates and licenses often check timestamps, and a mismatch of more than 72 hours can lead to activation issues.
Nessus offers both online and offline activation options. Offline activation is particularly useful for Nessus installations that do not have direct internet access. It involves obtaining an activation code from the Nessus website, which is then applied to the Nessus scanner.
The terminal will output a unique string of characters known as your . Copy this code exactly as it appears. Step 4: Download the New License and Plugin Set If you change the network interface card (NIC),
The "Nessus Offline Activation License Already in Use" error typically occurs when there's a mismatch or conflict with the license information. Here are some common causes:
This error triggers because Tenable associates your specific product license key with a unique hardware fingerprint (Challenge Code). If you attempt to apply the same license key to a new installation, a migrated server, or even a rebuilt virtual machine without clearing the old instance, Tenable’s activation server blocks the request to prevent unauthorized concurrent use.
You re-installed the OS or upgraded the hardware, changing the machine fingerprint. Tenable Discussions Tenable’s Nessus is the gold standard
If the local installation is corrupted, you can perform a full reset of the local scanner settings using nessuscli fix --reset-all before attempting the new offline registration. Update License Offline (Tenable Nessus 10.11)
Run the following command to register the offline license file you transferred:
Modifying the virtual machine (VM) resources, changing the Network Interface Card (NIC), or updating the OS MAC address, which alters the Challenge Code.
