Use the Tenable Community Portal to monitor which activation codes are in use.

Confirm the reset. The status will update to show the code is now available for a new installation. 2. Perform the Offline Activation

To resolve this and successfully activate your offline instance, you must reset the activation code through the Tenable Support Portal or Community. Step 1: Reset the Activation Code

Improperly completing the offline registration steps can lock the license in a "pending" state.

If you have tried these steps and are still experiencing issues, you may need to contact Tenable Support to have them manually reset the license on their end.

If your license is a free Nessus Essentials license (limited to scanning up to 16 IP addresses), the simplest resolution is often to obtain a new activation code using a different email address. Since free licenses carry no monetary cost, Tenable allows you to generate a fresh activation code without going through the deactivation process. The process is as follows:

Copy this alphanumeric string; you’ll need it for the next step.

Check if the license appears active on the current machine. If it does but you're still receiving an error, you may need to completely deactivate it before proceeding.

: C:\Program Files\Tenable\Nessus\nessuscli.exe fetch --deactivate . 3. Restart the Offline Activation Process

Despite best efforts, some situations require professional assistance. Contact Tenable Support when:

Release or reassign license via Tenable portal / support

on the machine currently holding the license. Navigate to the Nessus installation directory : Windows: C:\Program Files\Tenable\Nessus\ Linux: /opt/nessus/sbin/ Run the de-registration command : nessuscli fetch --challenge Use code with caution. This will give you a challenge code.

Nessus Offline Activation License Already In Use Jun 2026

Use the Tenable Community Portal to monitor which activation codes are in use.

Confirm the reset. The status will update to show the code is now available for a new installation. 2. Perform the Offline Activation

To resolve this and successfully activate your offline instance, you must reset the activation code through the Tenable Support Portal or Community. Step 1: Reset the Activation Code

Improperly completing the offline registration steps can lock the license in a "pending" state. nessus offline activation license already in use

If you have tried these steps and are still experiencing issues, you may need to contact Tenable Support to have them manually reset the license on their end.

If your license is a free Nessus Essentials license (limited to scanning up to 16 IP addresses), the simplest resolution is often to obtain a new activation code using a different email address. Since free licenses carry no monetary cost, Tenable allows you to generate a fresh activation code without going through the deactivation process. The process is as follows:

Copy this alphanumeric string; you’ll need it for the next step. Use the Tenable Community Portal to monitor which

Check if the license appears active on the current machine. If it does but you're still receiving an error, you may need to completely deactivate it before proceeding.

: C:\Program Files\Tenable\Nessus\nessuscli.exe fetch --deactivate . 3. Restart the Offline Activation Process

Despite best efforts, some situations require professional assistance. Contact Tenable Support when: If you have tried these steps and are

Release or reassign license via Tenable portal / support

on the machine currently holding the license. Navigate to the Nessus installation directory : Windows: C:\Program Files\Tenable\Nessus\ Linux: /opt/nessus/sbin/ Run the de-registration command : nessuscli fetch --challenge Use code with caution. This will give you a challenge code.