To resolve the issue:

1. On the Deep Security Manager console, go to Computers tab, then select the affected agent and delete it.
2. Disable the self-protection of Deep Security Agent or Deep Security Relay, if needed.
3. Deactivate the agent from the client via command line.
   1. Use RDP to connect to the primary relay.
   2. Open a command prompt as an administrator.
   3. Run the following command:

      cd C:\Program Files\Trend Micro\Deep Security Agent
      dsa_control.cmd -r

4. Stop all Trend Micro Deep Security Agent related services.
5. Close the agent icon from the taskbar.
6. Open the Windows explorer and access C:\programdata\.
7. Rename the Trend Micro folder to "Trend Micro_OLD".
8. Start all the Trend Micro related services.
9. Open the Deep Security Agent program. The icon should now re-appear on the taskbar, and then wait until it shows "Not Activated".
10. Re-add the computer object to the Deep Security Manager console and re-activate the agent.