[Plugin: Better WP Security] Plugins and Themes directory uploads can not be found

I am working with WordPress since a week. Have done a new installationdone. Then I installed the plugins – Better WP Security. This renamed the wp-document directory.
Everything looks to works fine in WordPress, but I cannot install plugins and themes. I can do that with ftp, and uploading themes and plugins they are working.

But I would like it very much if I could the plugins and themes installation working in WordPress again. In the support forum here, I found that to do that I had to set the wp-config.php to my own content path:
define( ‘WP_CONTENT_DIR’, $_SERVER[‘DOCUMENT_ROOT’] . ‘/blog/wp-content’ );
define( ‘WP_CONTENT_URL’, ‘http://mysite.nl/wp-content’);
I did this, but I still keep the exact same error message. That is, for example bij uploading theme Bilions :
Warning: touch() [function.touch]: Unable to create file /var/www/vhosts/mysite.nl/httpdocs/wp-content/uploads/billions.tmp because No such file or directory in /var/www/vhosts/mysite.nl/httpdocs/wp-admin/includes/file.php on line 177
Warning: unlink(/var/www/vhosts/mysite.nl/httpdocs/wp-content/uploads/billions.tmp) [function.unlink]: No such file or directory in /var/www/vhosts/mysite.nl/httpdocs/wp-admin/includes/file.php on line 489

http://wordpress.org/extend/plugins/better-wp-security/