The Hosting company has been excellent and helped restore to an earlier point.
The site is back to where I left it on a new placeholder url
I have deactivated all the conflicting plugins.
We now need to migrate the site to the launch url.
Cornerstone so far has not thrown an error.
For everyones benefit there I can tell you X theme + Cornerstone and some WP plugins don't mix.
Its one of these three
I really don't want anyone to go through the pain I have it took 5 days to get the site working !