In Use _top_: Nessus License Already

Sometimes, you aren't migrating, but you are trying to re-register the same scanner because the GUI is acting up.

: Updating your server's CPU, motherboard, or network card can change the host fingerprint, making the license server think you are trying to activate on a new machine. nessus license already in use

If you are using Nessus Essentials (the free version) or have access to the Tenable portal, you can usually unlink the old scanner yourself. Sometimes, you aren't migrating, but you are trying

Once unlinked, the activation code is freed up. You can now go back to your new scanner interface and enter the code again. It should register instantly. you aren't migrating

: If you are locked out due to frequent host changes, you must contact Tenable Support for a manual reset.