Nessus Offline Activation License Already In Use Exclusive

If the above fails, the license is likely hard-locked in Tenable’s backend. This often happens with expired trial licenses that were never properly deactivated.

Before attempting a fix, collect the following information from your offline Nessus server: nessus offline activation license already in use

However, this process breaks down with one of the most frustrating and cryptic errors in Tenable’s ecosystem: If the above fails, the license is likely

: Click "Manage Product" and then select "Reset Product Activation" (sometimes shown as a "Reset" link next to the code). If the above fails

If you built a Nessus scanner on a VM template, then cloned that VM to create a second scanner, both VMs will share the same MAC address (if not regenerated) or the same system UUID. Tenable sees this as one licensed device trying to activate twice.