No need to apologise what so ever - I am extremely grateful for your efforts and willingness to help.
The changes you suggested seem to have worked - I can open the web interface. I've not yet attempted the configuration as I've not yet installed all the drives I wish to include - I'll probably install the drives and configure in a single attempt rather than risk making changes to an existing configuration at a later date.
Something that may be useful to others - when I first tried to open the flexraid web interface, the page opened but appeared stuck in some sort of repeating launch cycle. I usually use chrome as a browser, so opened firefox and tried but had the same thing happen however firefox indicated that I needed to update/install adobe flash. Once flash was installed I got a stable flexraid screen that I can 'interact' with.
Ensuring flash is installed might prevent others from experiencing my problem. Incidently, once flash was installed the web inteface functioned correctly in chrome also.
Thanks again Ian

Mike