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

Re-run offline activation with correct file

: Run nessuscli fetch --challenge on the offline system.

: Verify the details and click "Yes" . Your code is now "free" and ready for a new installation. 2. Generate a New Challenge Code

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.