Do not upload the header and images

What’s in your .htaccess?

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

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [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).*) $1 [L]
RewriteRule  ^[_0-9a-zA-Z-]+/(.*\.php)$ $1 [L]
RewriteRule . index.php [L]

In 3.5.1 your images should still be in /wp-content/blogs.dir/2/… since you upgraded from 3.3

However the error you’re getting is a PHP error.

https://videoblogi.website.pl/wp-includes/ms-files.php?file=/2013/03/randkink.jpg is a 404 so I know that you don’t have the httpd.conf set up right.

Is it set to AllowOverride Options All?

I had no updated network, but on updated still did not work.

Same answer.

Look at your httpd.conf file on the server.

Is it set to AllowOverride Options All?

I updated anew 3.5.1

And the issue went away?

yes and it works well