diff --git a/application/models/QuestionTheme.php b/application/models/QuestionTheme.php
index c020221997d..6f4549ff838 100644
--- a/application/models/QuestionTheme.php
+++ b/application/models/QuestionTheme.php
@@ -529,7 +529,7 @@ public static function uninstall($oQuestionTheme)
         }
 
         // todo optimize function for very big surveys, eventually in yii 2 or 3 with batch processing / if this is breaking in Yii 1 use CDbDataReader $query = new CDbDataReader($command), $query->read()
-        $aQuestions = Question::model()->findAll(
+        $aQuestions = Question::model()->count(
             'type = :type AND question_theme_name = :theme AND parent_qid = :parent_qid',
             [
                 ':type'       => $oQuestionTheme->question_type,
diff --git a/application/models/services/ThemeQuestionAttributeProvider.php b/application/models/services/ThemeQuestionAttributeProvider.php
index d0dc221c844..0d17a49fdee 100644
--- a/application/models/services/ThemeQuestionAttributeProvider.php
+++ b/application/models/services/ThemeQuestionAttributeProvider.php
@@ -43,10 +43,10 @@ protected function getAttributesFromQuestionTheme($questionThemeName, $questionT
         if ($questionTheme !== null) {
             $xmlFilePath = $questionTheme['xml_path'] . '/config.xml';
             $extensionConfig = \ExtensionConfig::loadFromFile($xmlFilePath);
-            $xmlAttributes = $extensionConfig->getNodeAsArray('attributes');
         }
 
-        if (!empty($xmlAttributes)) {
+        if (!empty($extensionConfig)) {
+            $xmlAttributes = $extensionConfig->getNodeAsArray('attributes');
             if (!empty($xmlAttributes['attribute']['name'])) {
                 // Only one attribute set in config: need an array of attributes
                 $xmlAttributes['attribute'] = array($xmlAttributes['attribute']);