The first step for debugging these particular should always involve deleting your browser cache and potentially testing a different browser, even though this doesn't appear to be a primary suspect here.
More likely would be a corruption of /etc/config/uhttpd or /etc/config/luci, both of which you could restore from their /rom/etc/config/ backups - if that doesn't help either, a factory reset could be a natural next step (as it would re-establish potentially deleted packages).
It appears I installed an additional package using the GUI and it was in an attempt to restrict internet access.
Nothing appears to happen until I rebooted the router..
I've removed the offending HTTP server and it's rebooting...
YES!! working.... thanks for all the help guys.. Excellent!!!
Cheers..