can't save settings

It may come down to more than one reason.

Have you tried different browser/computer?

Exactly same behavior in Chrome, IE, FireFox, Safari
??

Have you tried:
– deactivating ALL plugins temporarily to see if this resolves the problem. If this works, re-activate them individually (one-by-one) to find the problematic plugin(s). If you can’t get into your admin dashboard, try deactivating via FTP or SFTP or whatever file management application your host provides.
– switching to the unedited default, core-bundled Theme (such as Twenty Twelve, Twenty Thirteen or Twenty Fourteen) for a moment using the WP dashboard to rule out any theme-specific issue. If you don’t have access to your admin area, you can switch to the default theme by renaming your current theme’s folder in wp-content/themes and adding “-old” to the end of the folder name using via FTP or SFTP or whatever file management application your host provides. Alternately, you can remove other themes except the default theme. That will force your site to use it.
– resetting the plugins folder by FTP or PhpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems (because the hooks remain unless plugins completely removed or some plugins stick around in cached files. So by renaming the folder, you break them and force them inactive).
– If the above troubleshooting steps fail to resolve the issue, try MANUALLY re-uploading all files and folders EXCEPT the wp-config.php file and the /wp-content/ directory from a fresh download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones. Read the Manual Update directions first!

This is a new install – no changes to theme or plugins – it’s exactly the way wordpress woke up.

sigh

I can, of course, manually upload the site, but… As I mentioned, I suspect that this is either a .htaccess problem or server or PHP setting or the like. What could cause this behavior?

It could be a number os reasons. Basic troubleshooting steps are a process of elimination.

Prior to .htaccess, I was getting this error when I tried to save Settings/General:

Maybe that will help?

Forbidden

You don’t have permission to access /wp-admin/options.php on this server.

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

Do you have access to server error logs? They might provide some clues to what’s happening.

[Thu Mar 27 17:05:45 2014] [error] [client 108.212.220.217] File does not exist: /home/cecily/public_html/403.shtml, referer: https://cecilypalamara.com/wp-admin/options-general.php
[Thu Mar 27 17:03:39 2014] [error] [client 108.212.220.217] File does not exist: /home/cecily/public_html/403.shtml, referer: https://cecilypalamara.com/wp-admin/options-general.php
[Thu Mar 27 16:48:24 2014] [error] [client 108.212.220.217] File does not exist: /home/cecily/public_html/404.shtml

These are the only errors – this is a second brand new fresh out of the box site on the same server with same symptom…

So no plugins, a default WordPress theme, on a fresh install of WordPress on a Linux/Apache/MySQL/PHP (shared) server?

You don’t have any “defined” paths in your wp-config.php file? Don’t post any of your wp-config.php code here! Just look in the file and see if you have something like this in your wp-config:

define( 'WP_SITEURL', 'https://' . $_SERVER['SERVER_NAME'] . '/path/to/wordpress' );

Nope, I have nothing like
define( ‘WP_SITEURL’, ‘https://’ . $_SERVER[‘SERVER_NAME’] . ‘/path/to/wordpress’ );
in config.php

my host reports that they could see that one of the server mod_security settings was causing the issue – they ‘white listed the rule’ and all is now working normally.

Thanks all of you for your concern and assistance – problem is resolved.