Installation of Symantec Endpoint Protection 12.1 RU5 fails with error "3- PAR signature failure, not running 3-PAR"

book

Article ID: 158390

calendar_today

Updated On:

Products

Endpoint Protection

Issue/Introduction

The installation of Symantec Endpoint Protection 12.1 RU5 (SEP) fails with the error "3-PAR signature failure, not running 3-PAR" when the installation is in interactive mode. When the installation is in silent mode, this error message will be logged in the following log file: C:\ProgramData\Symantec\Setup\Setup_s.log

 
This issue only occurs when the setting "Automatically uninstall existing security software" is enabled in the SEP client install settings.

Cause

This issue occurs when the root certificate "VeriSign Class 3 Public Primary Certification Authority - G5" is not present in the local computers Trusted Root Certificate Store. This certificate is used to verify the signatures of files used in the SEP installation.

Resolution

There are two possible solutions to this issue.
 
Update Windows Root Certificates (Recommended)
The Microsoft KB Document 931125 explains how to update Window's list of root certificates. The update will contain the needed certificate.
 
Manually Download and Install the Missing Root Certificate
Download and install the certificate "VeriSign Class 3 Public Primary Certification Authority - G5" from the following Symantec webpage: Download Primary PCA Root Certificates