Images not found on subsites because of the rewrite issue?

Hi!
Im using WP 3.5 and whenever I upload a file through subsite wp-admin it wont be displayed.
The image will be displayed with url path:
http://www.domain.ltd/en/assets/sites/2/image.png

Where “en” is the subsite subfolder and 2 is the subsite id.
But when WP tries to display it, there is WP page not found .
And I can access the file through:
http://www.domain.ltd/assets/sites/2/image.png/
(without the subsite subfolder)

.htaccess:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) wp/$2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ wp/$2 [L]
RewriteRule . index.php [L]

Everything else works but images.
Can please somebody help me?
No plugins used.