400 Bad Request

The server could not comply with the request since it is either malformed or otherwise incorrect.

Cannot decode URL parameter keywords: ['thema_praventionsthema%3AGewaltpr%C3%A4vention%2Bschulstufe_klasse_stufe%3ASek 2. Klasse%2Bschulstufe_klasse_stufe%3APS 4. Klasse']