Plesk 12：从文档根目录外链接Php文件不起作用（纯html会）

Hi i am using Plesk12 on Ubuntu14.04 with Apache2 an php5 as Apache-Modul. I have tried a lot of settings for my vhost, but Apache don´t executes php files from outside the document root. At the moment i use this setting for my vhost:

<Directory /var/www/vhosts/***.de/httpdocs/>
    Options Indexes FollowSymLinks MultiViews
</Directory>

I have this problem only with php files from ouside the document root, if I link a php-file inside the codument-root it works find, if i link in pure html it also works fine.

Watched the apache logs but could not find an info.

Anybody an idea?