Error during installation process (qt.591.gcc_64)

I have a problem installing Qt on Red Hat Enterprise 6.8. I have tried to install QT 5.9.1 using the full enterprise version file: qt-enterprise-linux-x64-5.9.1.run and the unified version file: qt-unified-linux-x64-3.0.1-online.run. I have tried both Qt installation files on two different instances of Red Hat 6.8; a development server and a basic desktop. I get the same error from both Qt installation files on both systems. I have also tried earlier version (5.9.0, 5.60, 4.8.7) the also fail (just a slightly different error msg). I eventually just tried using just minimal options with only the Desktop gcc 64-bit, Installer Framework 2.0/3.0 (each and together) and the Qt Quick Compiler. 

The error is displayed in a popup error window as:

Error during installation process (qt.591.gcc_64):
The output of
/home/pmcude/Qt5.9.1/5.9.1/gcc_64/bin/qmake -query
is not parseable. Please file a bugreport with this dialog https://bugreports.qt-project.org.
output: ""
 
Note: I have installed Qt 5.9.1 on Red Hat 7.4 with no problem. I see a similar issue reported (QTBUG-61825) when installing in another environment on Debian Sqeeze.
Any help would be greatly appreciated as I am completely stuck Thank you.