On your advice, after it failed to boot up again, I blocked with LS but it didn't force it to work. Hopefully now that it is blocked it won't cause it to fail again.

Can I ask how you knew what IP address you needed to for this to work? Might the address be different on my iMac?

I have a real problem with CWS, I can't get it to quit and I have to force quit and now and again it won't load so I have to remove the EFI Rel3.Fiery Command WorkStation.dj file get it to work again.