wp-admin suddenly goes to dashboard

Hi,
Site is http://cfscp.org/dev/ using Vantage theme.
All has been normal working on this site until today. Home page has no admin bar; when I type url with wp-admin attached, it goes not to home page but to dashboard. I can’t edit home page from the page, as I could before today.

Also, the home page isn’t part of the menu nor listed in ‘pages’ (which may be the way I originally set it up somehow).

Thanks for any help.