Nessus Scanner Statuses

You can view the status for scanners, as described in View Your Nessus Scanners.

Status Description Recommended Action
Authentication Error could not authenticate to the scanner using the credentials you provided.

Check your scanner configuration settings and confirm the Username and Password options specify valid login credentials for the scanner.
Certificate Mismatch could not confirm the validity of the SSL certificate presented by the scanner.

Do one of the following:

Connection Error cannot connect to the scanner because the scanner is unreachable or does not exist at the IP address or hostname provided.

Do one or both of the following:

  • Check your scanner configuration and confirm the Host option specifies the correct IP address or hostname for the scanner.
  • Confirm the network devices and firewalls between and the scanner are configured to permit network traffic.
Connection Timeout connected to the scanner but timed out waiting for a reply. Contact your network administrator for troubleshooting assistance.
Invalid Configuration The scanner attempted to connect to a scanner on port 0.

Do one or both of the following:

Plugins Out of Sync The plugin sets on the scanner do not match the plugin sets in For troubleshooting assistance, see the knowledge base article.
Protocol Error connected to the scanner but the scanner returned an HTTPS protocol negotiation error. Contact your network administrator for troubleshooting assistance.
Reloading Scanner The scanner is temporarily unable to run scans because Nessus is restarting on the scanner. None.
Updating Plugins is performing a plugin update on the scanner.

You may want to schedule plugin updates to run a few hours before your scheduled scans. For more information, see Edit Plugin and Feed Settings and Schedules.

If a scanner has a persistent Updating Plugins status, the plugin update have been interrupted. For troubleshooting assistance, see the knowledge base article.

Updating Status is refreshing the status of the scanner. Scanners can continue to run scans while refreshes the status.

Note: automatically refreshes scanner statuses every 15 minutes.

If you create a new scanner, edit a scanner, or manually refresh the status using the Update Status option, refreshes the status of the scanner on demand.

Upgrade Required

The version of Nessus on the scanner is unsupported and requires an upgrade. cannot perform scans with or update plugins for scanners running unsupported versions of Nessus. For minimum Nessus scanner version requirements, see the Release Notes for your version.

Upgrade to a supported version of Nessus, as described in Upgrade Nessus in the Nessus User Guide.

User Disabled A user disabled the scanner.

Edit your scanner configuration and click the Enabled toggle to re-enable the scanner.

For more information about scanner options, see Nessus Scanners.

Working The scanner is connected to and able to run scans. None.