WSSA user cannot connect to workstation after upgrade despite MCU parameter enabled


Article ID: 209387


Updated On:


Web Security Service - WSS


WSSA 6.1.1 installed on Windows host

Installation run with MCU=1 parameter to make sure enabled (msiexec -I C:\downloads\wssa-installer.msi /passive MCU=1)

Admin then tried to deploy the WSSA 7.2.1 MSI file with Microsoft SCCM 

WSSA 7.2.1 install works but user cannot connect to the host afterwards afterwards

  - The installation works when an interactive user is logged into workstation but fails if no user logged in


The MCU option only takes effect on a new install - so they need to uninstall 6.x first, and then install 7.x with the MCU option.

Only if you are changing your MCU value do you need to do a clean install. 


When the issue happens, uninstall WSSA 6.x first, and then install WSSA 7.x with the MCU option

f you have already installed with MCU (i.e. when upgrading from 7.1 to 7.2 - if you installed 7.1 with MCU), then there isn't any need at all to specify's already installed that way.


Additional Information

It is not recommended that an organization push out MCU=1 to all their endpoints.  It should be used in RDP server scenarios only - when you are installing WSSA on an RDP server.