Wordpress Link to plugins folder does not work

[Jörg Possin]

Hi!

I installed Wordpress on a 14.04 server and use the setup-mysql in /usr/share/doc/wordpress/examples to create DB table and folder in filesystem.
The script created a /srv/ww/wp-content/$domain folder which contains Symlinks to folders plugins, themes and languages under /var/lib/wordpress/wp-content.

Then I custimize the /etc/apache2/sites-available/000-defauklt to get access to Wordpress. It works: Wordpress is loading and I can install themes and activate them.
But if I install a plugin (it will be installed by wordpress) and try to activate it the wordpress php code searches not the plugin php code under /var/lib/wordpress/wp-content/plugins but under /usr/share/wordpress/wp-content/plugins.