They will manually run a database query on Tenable’s backend to disassociate the activation code from the stale Challenge Code. This takes 24–48 hours for Standard support, 2–4 hours for Premium.
Write down this output. If this Challenge Code differs from the one you used during the first successful activation, you have found the mismatch. nessus offline activation license already in use
This will output a string like: d4f5e1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8 They will manually run a database query on
The "Nessus offline activation license already in use" error indicates the code is currently linked to an active scanner, requiring a reset via the Tenable Support Portal to free the license If this Challenge Code differs from the one
This command erases the registration information and clears the local configuration. 3. Complete the Offline Activation Process
If the problem persists after trying these steps, open a support ticket with Tenable. Provide them with your Activation Code and the output of nessus-fetch --challenge . They can manually clear the lock from their backend database.