NOTE: FortiNAC is now named FortiNAC-F. For post-9.4 articles, see FortiNAC-F. FortiNAC is a zero-trust network access solution that provides users with enhanced visibility into the Internet of Things (IoT) devices on their enterprise networks.
Article Id 197292
"Error Scanning" displays while attempting to scan host in Host View.

There are a couple of messages that could display when attempting to scan via the Hosts View using the Scan Host(s) option.

Message 1:  Error scanning host xxx Attempting to scan for null Failed to determine Policy... Try again in 10 minutes.

This means the host did not match any Endpoint Compliance policy. Verify by right clicking on host record and selecting Policy Details. The Endpoint Compliance tab content is empty if no policies matched.

Message 2:  Error scanning host xxx Failed to find live (online+communicating) adapter in HostRecord... Try Again In 10 Minutes.

This means the Persistent Agent on that host has not been heard from in awhile and presumed to no longer be responding. This could be due to various factors:
- The host shows all its adapters offline (gray icon).
- NAC has not received any communication from the agent (including "Hello" packets which are sent regularly if the agent is running).

Message 1 Solution:  
Review User/Host profile of the Endpoint Compliance policy the host should have matched to figure out what criteria is missing.

Message 2 Solution:
1. Verify the host shows online in Host View.
2. If it does, try sending a message (right click on Host > Send Message) to see if the agent is able to receive it.  If unable to send message, the cause could be one of the following:

- The agent may no longer be running and needs to be restarted.  Refer to the related KB article below.

- UDP 4567 traffic is being blocked from that agent (either on a firewall on the endstation or someplace else on the network).

Related Articles

Technical Note: Persistent Agent communication ports

Technical Note: Lost Contact with Persistent Agent After Updating From Version 2.x to 3.x or Higher

Technical Note: Windows Persistent Agent logs

Technical Note: macOS Persistent Agent logs

Technical Note: How to restart the Persistent Agent