Summary
The WFBS Security Agent (SA) failed to install. You got the following error message instead:
"Installation Unsuccessful."

One of the following error messages may also appear:
- "The installer could not install the required solution platform. - Error code 303, Error code 304, Error code 30"
- "The installer could not install the required plug-ins. - Error code 321"
- "The installer could not copy the required files. - Error code 331"
- "The installer could not start the Security Agent. - Error code 351"
Details
To resolve the issue, do the following:
- Manually remove the old Security Agent using the SA Uninstall Tool. Contact Trend Micro Techincal Support to get assitance with using the Uninstall Tool.
- Reinstall the Security Agent (SA). If you need more help with reinstalling the SA, refer to this article: Different Security Agent installation methods in WFBS