diff --git a/Controller/ApiBillController.php b/Controller/ApiBillController.php
index ddcb1bf..400c898 100755
--- a/Controller/ApiBillController.php
+++ b/Controller/ApiBillController.php
@@ -1173,7 +1173,7 @@ final class ApiBillController extends Controller
         }
 
         /** @var \Modules\Editor\Models\EditorDoc $model */
-        $model = $response->get($request->uri->__toString())['response'];
+        $model = $response->getDataArray($request->uri->__toString())['response'];
         $this->createModelRelation($request->header->account, $request->getDataInt('id'), $model->id, BillMapper::class, 'bill_note', '', $request->getOrigin());
     }
 
diff --git a/Controller/ApiPurchaseController.php b/Controller/ApiPurchaseController.php
index 87494b7..1c899bf 100755
--- a/Controller/ApiPurchaseController.php
+++ b/Controller/ApiPurchaseController.php
@@ -81,7 +81,7 @@ final class ApiPurchaseController extends Controller
 
             $this->app->moduleManager->get('Billing', 'Api')->apiBillCreate($billRequest, $billResponse, $data);
 
-            $billId = $billResponse->get('')['response']->id;
+            $billId = $billResponse->getDataArray('')['response']->id;
 
             // Upload and assign document to bill
             $mediaRequest                  = new HttpRequest();
@@ -98,7 +98,7 @@ final class ApiPurchaseController extends Controller
             $this->app->moduleManager->get('Billing', 'Api')->apiMediaAddToBill($mediaRequest, $mediaResponse, $data);
 
             /** @var \Modules\Media\Models\Media[] $uploaded */
-            $uploaded = $mediaResponse->get('')['response']['upload'];
+            $uploaded = $mediaResponse->getDataArray('')['response']['upload'];
             if (empty($uploaded)) {
                 throw new \Exception();
             }
diff --git a/Controller/ApiTaxController.php b/Controller/ApiTaxController.php
index 39bb23d..cd1b997 100755
--- a/Controller/ApiTaxController.php
+++ b/Controller/ApiTaxController.php
@@ -107,7 +107,7 @@ final class ApiTaxController extends Controller
      *
      * @param RequestAbstract  $request  Request
      * @param ResponseAbstract $response Response
-     * @param mixed            $data     Data
+     * @param array            $data     Data
      *
      * @return void
      *
diff --git a/Models/BillElement.php b/Models/BillElement.php
index 922f6d8..9292ad7 100755
--- a/Models/BillElement.php
+++ b/Models/BillElement.php
@@ -273,12 +273,12 @@ class BillElement implements \JsonSerializable
         $element->singleProfitGross->setInt($element->singleSalesPriceGross->getInt() - $element->singlePurchasePriceGross->getInt());
         $element->totalProfitGross->setInt($element->quantity * ($element->totalSalesPriceGross->getInt() - $element->totalPurchasePriceGross->getInt()));
 
-        if (!empty($element->bill)
+        if ($element->bill->id !== 0
             && $item->getAttribute('subscription')->value->getValue() === 1
             && $element->item !== null
         ) {
             $element->subscription        = new Subscription();
-            $element->subscription->bill  = $element->bill;
+            $element->subscription->bill  = $element->bill->id;
             $element->subscription->item  = $element->item;
             $element->subscription->start = new \DateTime('now'); // @todo: change to bill performanceDate
             $element->subscription->end   = new SmartDateTime('now'); // @todo: depends on subscription type
diff --git a/Models/SalesBillMapper.php b/Models/SalesBillMapper.php
index 09467f9..9792788 100755
--- a/Models/SalesBillMapper.php
+++ b/Models/SalesBillMapper.php
@@ -122,7 +122,7 @@ final class SalesBillMapper extends BillMapper
     {
         $query = new Builder(self::$db);
 
-        /** @var false|array $result */
+        /** @var array $result */
         $result = $query->select('SUM(billing_bill_element_single_netsalesprice)', 'COUNT(billing_bill_element_total_netsalesprice)')
             ->from(self::TABLE)
             ->leftJoin(BillElementMapper::TABLE)
@@ -131,9 +131,9 @@ final class SalesBillMapper extends BillMapper
             ->andWhere(self::TABLE . '.billing_bill_performance_date', '>=', $start)
             ->andWhere(self::TABLE . '.billing_bill_performance_date', '<=', $end)
             ->execute()
-            ?->fetch() ?? false;
+            ?->fetch() ?? [];
 
-        return new FloatInt($result === false || ((int) ($result[1] ?? 0)) === 0 ? 0 : (int) (((int) $result[0] ?? 0) / ((int) $result[1])));
+        return new FloatInt(((int) ($result[1] ?? 0)) === 0 ? 0 : (int) (((int) ($result[0] ?? 0)) / ((int) $result[1])));
     }
 
     /**