[common] Correctif modèle Product

common/models/Product.php

         public function afterFind() {
                 if ($this->taxRate == null) {
                         $producer = Producer::searchOne(['id' => GlobalParam::getCurrentProducerId()]) ;
-                        $this->populateRelation('taxRate', $producer->taxRate);
+                        if($producer) {
+                                $this->populateRelation('taxRate', $producer->taxRate);
+                        }
                         //$this->populateRelation('taxRate', GlobalParam::getCurrentProducer()->taxRate);
                 }