Correctifs

producer/controllers/ProducerBaseController.php

             return $this->producer ;
         }
         else {
+            $slug = \Yii::$app->getRequest()->getQueryParam('slug_producer');
             $producer = Producer::find()
                 ->with('contact')
-                ->where(['slug' => \Yii::$app->getRequest()->getQueryParam('slug_producer')])
+                ->where(['slug' => $slug])
                 ->one() ;
             
             if($producer) {
                 $this->producer = $producer ;
                 return $this->producer ;
-            }   
+            }
             else {
-                throw new \yii\web\HttpException(404, 'Producteur introuvable');
+                throw new \yii\web\HttpException(404, 'Producteur introuvable ('.$slug.')');
             }
         }
     }