diff --git a/common/framework/parsers/dbquery/variablebase.php b/common/framework/parsers/dbquery/variablebase.php
index 255fcc375..fb9d40b9d 100644
--- a/common/framework/parsers/dbquery/variablebase.php
+++ b/common/framework/parsers/dbquery/variablebase.php
@@ -309,6 +309,11 @@ class VariableBase
 		{
 			list($is_expression, $value) = $this->getDefaultValue();
 		}
+		else
+		{
+			$is_expression = null;
+			$value = null;
+		}
 		
 		return [$is_expression, $value];
 	}
diff --git a/modules/document/document.controller.php b/modules/document/document.controller.php
index 7caa3946d..c17b1dca7 100644
--- a/modules/document/document.controller.php
+++ b/modules/document/document.controller.php
@@ -2463,7 +2463,7 @@ class documentController extends document
 			$list[$category_srl] = $category_list[$i];
 		}
 		// Create the xml file without node data if no data is obtained
-		if(!$list)
+		if(!isset($list) || !$list)
 		{
 			$xml_buff = "<root />";
 			FileHandler::writeFile($xml_file, $xml_buff);