As mentioned in the following post, you need to apply the following:
1. Make sure that you have imported the latest AV key in the LANDESK Console.
2. Run a Security scan on the client. Do not right-click a computer in the Console and select the Patch and Compliance scan option. This scan will not update the client. You can create a Security Scan task by selecting the Security Scan option from the "Create a task" drop-down list in the Agent Settings tool in the Console.
If this does not fix it, open a case with LANDESK Support to get help with it.
Or check the last section in this article: Error: "The AV license key is missing or expired"