Use another installation method in installing Security Agent:

1. Open the MAC terminal.
2. Enter the following syntax:

   sudo installer -pkg <package path> -target <mountpoint>

   For example:

   sudo installer -pkg /users/admin/Library/WFBS-SVC_Agent_Installer.pkg -target /

3. If the command is correct, you should see the following lines after entering it:
   
   Installer: Package name is Trend Micro Security
   Installer: Installing at base path /
   Installer: The install was successful
4. Verify if you have the Trend Micro icon on the Menu bar located in the upper right-hand section of your screen.

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