Hello everyone,
there is no green success message when the contact form/comment form is filled out correctly if FlatPress is located directly in the main document directory ($_SERVER['DOCUMENT_ROOT']). In addition, you may have to click “Send” twice for the message to be sent.

If FlatPress is located in a subdirectory, a green success message is displayed.

Conditions/ Setup:
FlatPress 1.3.1 release, standard theme, only standard plugins active except accessibleantispam and prettyurls, Commentcenter=allow all comments, no Akismet active.

Apache 2.4 on Debian, Xampp on Windows

My note:
I could not find out the cause. Maybe you should look at the utils_redirect() function.

My workaround:
Do not leave FlatPress in $_SERVER['DOCUMENT_ROOT'], but move it to a subdirectory.

So that FlatPress appears when the domain is called, the rewrite rule in the .htaccess in $_SERVER['DOCUMENT_ROOT'] must be adjusted as follows:

<IfModule mod_rewrite.c>
	RewriteEngine On
	RewriteRule ^\.htaccess$ - [F]
	RewriteBase /

	RewriteCond %{REQUEST_URI} !^/subdirectory/
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteRule ^(.*)$ /subdirectory/$1
	RewriteRule ^(/)?$ subdirectory/index.php [L]
</IfModule>

With best regards
Frank