Something I found after installing Citrix Secure Gateway (CSG) 3.1 on a server running Web Interface (WI) 5.0.1. It removed permissions from the “%ProgramFiles%\Citrix\Web Interface\5.0.1\Clients” folder and instructed it to inherrit from its parent.
Therefore, only the Administrators local group had full control.
This was causing problems for client updates and downloads via the CSG server.