I wasn't in my largest ring on my cassette and the top of the front cog, I don't ever ride like that so wouldn't be bothered by the clicking. The initial clicking was being in my full on hardest gear (as I I was descending on a large hill etc)
Thanks for all the advice, the derailleur is now moving again when I get the shifter going which is atleast an improvement on yesterday. But now it won't move into the top cog as the limit screw are off. Before I touch something I clearly don't understand that well again, ultegra 6800 FD, the screw furthest from the frame should set the outer limit correct? so if I turn that it should move it across? As at the moment I am turning it, but there is no movement.