The GUI installation of CA Spectrum fails on Linux with "Installer User Interface Mode Not Supported"
Missing the libXtst.so.6 i686 library
Use the following command run as root to install the libXtst-1.2.2-2.1.el7.i686 X.Org X11 libXtst runtime library:
yum install libXtst-1.2.2-2.1.el7.i686