Fehler: No result for the single row query: 'SELECT DISTINCT `Quizz`.`id` AS `Quizzid`, `Quizz`.`name` AS `Quizzname`, `Quizz`.`description` AS `Quizzdescription`, `Quizz`.`language` AS `Quizzlanguage`, `Quizz`.`title` AS `Quizztitle`, `Quizz`.`introduction` AS `Quizzintroduction`, `Quizz`.`scale_values` AS `Quizzscale_values`, `Quizz`.`conclusion` AS `Quizzconclusion`, CAST(CONCAT(COALESCE(`Quizz`.`name`, '')) AS CHAR) AS `Quizzfriendlyname` FROM `qz_quizz` AS `Quizz` WHERE (`Quizz`.`id` = '') '.