Write New post fails

While trying to publish a new post today from Front End, I get an odd error:

"Forbidden

You don't have permission to access /dashboard/write on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."

I have never seen this before.

I tried:

1. Posting to public, private, reg users only, and various categories = ng.
2. posting as a Super user = ng.
3. adding extra ACL to User (Public and Registered; had been Author only) = ng.
4. Investigated Blog Category permissions = seems correct, simple, logical.

ALSO: I can't upload image via Insert Media / Media Manager (says it "can't parse response," or "No Response")

— HOWEVER —

I can do all of the above, no problems, from the Back End/admin interface.

I included login infor in the tab below.
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Latest Joomla, latest EasyBlog, as of today.

Thanks in advance for your help. We JUST LAUNCHED and they're yelling at me.