The requested file is displayed over the index file, what should I do?

Question

htaccess

T
Such a thing. When I go to any page specified through include, the requested page and index page are displayed.
I suspect that the matter is in .htaccess. So I throw it here:
AddDefaultCharset utf-8
RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} /+[^\.]+$
RewriteRule ^(.+[^/ ])$ %{REQUEST_URI}/ [R=301,L]
RewriteRule \.(php|htm|swf|fla|xml|ico|jpg|gif|png|js|css)$ - [L]
RewriteRule ^.* $index.php[NC,L]