I was using .htaccess code to remove .php extension for all my web pages. Here\'s the code I use:
RewriteEngine On
RewriteCond /%{REQUEST_FILENAME}.php -f
Re
It seems like the slash at the end of your rule might be there, or it might not. Adding a ? makes it optional, so that mysite.com/about and mysite.com/about/ will both match.
RewriteEngine On
RewriteRule ^([a-zA-Z0-9_-\s]+)/?$ /$1.php
It's hard to say if this is what's causing your problem, or if something else is, though. Does mysite.com/about.php also give you an error?