To resolve this issue, do the following:

1. Test the connection between the agent and server using the commands:
   • Ping <Apex One (Mac) server IP Address>
   • nc -vz <Apex One (Mac) server IP Address> <port>
   • Ping <Apex One (Mac) server FQDN>
   • nc -vz <Apex One (Mac) server IP Address> <port>
    

   • The default port is 61617.
   • There should be 2 or 4 connection test that results to PASS to ensure the connection.

    
2. Ensure that the <port> used is open for agent-to-server communication.
3. Check if the Apex One SSL certificate is expired. If expired, renew the certificate by referring to this article.
4. Open Command Prompt with admin rights, navigate to ..\Trend Micro\Apex One\Addon\TMSM\, and then launch the restart_TMSM.bat file. This will restart the service to make the TMSM agent package reflect the new changes.
5. Get the install package from Apex One (Mac) web console > Agents > Agent Setup Files and redo the agent installation on the Mac computer.

If the issue still persists, contact Trend Micro Technical Support.