SOLVED (was: Re: Help- Nobody can create or edit pages)
A great big THANK YOU to Sylvie and Rick and in particular Louis-Philippe, who all responded to my cry for help.
TURNS OUT that is you set the UserPages prefix to nothing, then somehow it locks up the whole site for editing.
Setting a non-blank prefix turns editing back on.
Jeeeeeeepers, I would not have made that connection.
Thanks Folks!