Never finds fitting entries

Created by: phischdev

Hey, I've got the following problem: Whatever existing category I enter in

<DPL>
  category = PR.Artikel
</DPL>

the extension always returns Extension:DynamicPageList (DPL), version 3.1.1: Warnung: Kein passender Eintrag gefunden!" which by the way is german and means ~ Alert: no fitting entry found.

I'm using MediaWiki in german and with the BlueSpice Extension(s). What could be the problem?

Many thanks in advance