diff --git a/modules/comment/comment.controller.php b/modules/comment/comment.controller.php
index 06d74963a..7a4010b00 100644
--- a/modules/comment/comment.controller.php
+++ b/modules/comment/comment.controller.php
@@ -245,10 +245,14 @@
             if($oCacheHandler->isSupport()) 
             {
             	$cache_object = $oCacheHandler->get('comment_list_document_pages');
-            	foreach ($cache_object as $object){
-            		$cache_key = $object;
-                	$oCacheHandler->delete($cache_key);
-            	}
+            	if(isset($cache_object) && is_array($cache_object)){
+		    foreach ($cache_object as $object){
+			$cache_key = $object;
+			$oCacheHandler->delete($cache_key);
+		    }
+		}elseif(!is_array($cache_object)) {
+		    $oCacheHandler->delete($cache_key);
+		}
                 $oCacheHandler->delete('comment_list_document_pages');
             }
             return $output;
@@ -332,10 +336,14 @@
             if($oCacheHandler->isSupport()) 
             {
             	$cache_object = $oCacheHandler->get('comment_list_document_pages');
-            	foreach ($cache_object as $object){
-            		$cache_key = $object;
-                	$oCacheHandler->delete($cache_key);
-            	}
+            	if(isset($cache_object) && is_array($cache_object)){
+		    foreach ($cache_object as $object){
+			$cache_key = $object;
+			$oCacheHandler->delete($cache_key);
+		    }
+		}elseif(!is_array($cache_object)) {
+		    $oCacheHandler->delete($cache_key);
+		}
                 $oCacheHandler->delete('comment_list_document_pages');
             }
             return $output;
@@ -406,10 +414,14 @@
             if($oCacheHandler->isSupport()) 
             {
             	$cache_object = $oCacheHandler->get('comment_list_document_pages');
-            	foreach ($cache_object as $object){
-            		$cache_key = $object;
-                	$oCacheHandler->delete($cache_key);
-            	}
+            	if(isset($cache_object) && is_array($cache_object)){
+		    foreach ($cache_object as $object){
+			$cache_key = $object;
+			$oCacheHandler->delete($cache_key);
+		    }
+		}elseif(!is_array($cache_object)) {
+		    $oCacheHandler->delete($cache_key);
+		}
                 $oCacheHandler->delete('comment_list_document_pages');
             }
             return $output;
@@ -469,10 +481,14 @@
             if($oCacheHandler->isSupport()) 
             {
             	$cache_object = $oCacheHandler->get('comment_list_document_pages');
-            	foreach ($cache_object as $object){
-            		$cache_key = $object;
-                	$oCacheHandler->delete($cache_key);
-            	}
+            	if(isset($cache_object) && is_array($cache_object)){
+		    foreach ($cache_object as $object){
+			$cache_key = $object;
+			$oCacheHandler->delete($cache_key);
+		    }
+		}elseif(!is_array($cache_object)) {
+		    $oCacheHandler->delete($cache_key);
+		}
                 $oCacheHandler->delete('comment_list_document_pages');
             }
 
diff --git a/modules/document/document.controller.php b/modules/document/document.controller.php
index b321c92b4..1516e910b 100644
--- a/modules/document/document.controller.php
+++ b/modules/document/document.controller.php
@@ -244,10 +244,14 @@ class documentController extends document {
             $cache_key = 'object:'.$obj->document_srl;
             $oCacheHandler->delete($cache_key);
             $cache_object = $oCacheHandler->get('module_list_documents');
-            foreach ($cache_object as $object){
-            	$cache_key_object = $object;
-                $oCacheHandler->delete($cache_key_object);
-            }
+            if(isset($cache_object) && is_array($cache_object)){
+		foreach ($cache_object as $object){
+		    $cache_key_object = $object;
+		    $oCacheHandler->delete($cache_key_object);
+		}
+	    }elseif(!is_array($cache_object)) {
+		$oCacheHandler->delete($cache_key_object);
+	    }
             $oCacheHandler->delete('module_list_documents');
         }
 
@@ -411,10 +415,14 @@ class documentController extends document {
             $cache_key = 'object:'.$obj->document_srl;
             $oCacheHandler->delete($cache_key);
             $cache_object = $oCacheHandler->get('module_list_documents');
-            foreach ($cache_object as $object){
-            	$cache_key_object = $object;
-                $oCacheHandler->delete($cache_key_object);
-            }
+            if(isset($cache_object) && is_array($cache_object)){
+		foreach ($cache_object as $object){
+		    $cache_key_object = $object;
+		    $oCacheHandler->delete($cache_key_object);
+		}
+	    }elseif(!is_array($cache_object)) {
+		$oCacheHandler->delete($cache_key_object);
+	    }
             $oCacheHandler->delete('module_list_documents');
             //remove document item from cache
             $cache_key = 'object_document_item:'.$obj->document_srl;
@@ -498,10 +506,14 @@ class documentController extends document {
             $cache_key = 'object:'.$document_srl;
             $oCacheHandler->delete($cache_key);
             $cache_object = $oCacheHandler->get('module_list_documents');
-            foreach ($cache_object as $object){
-            	$cache_key_object = $object;
-                $oCacheHandler->delete($cache_key_object);
-            }
+            if(isset($cache_object) && is_array($cache_object)){
+		foreach ($cache_object as $object){
+		    $cache_key_object = $object;
+		    $oCacheHandler->delete($cache_key_object);
+		}
+	    }elseif(!is_array($cache_object)) {
+		$oCacheHandler->delete($cache_key_object);
+	    }
             $oCacheHandler->delete('module_list_documents');
             $cache_key = 'object_document_item:'.$document_srl;
             $oCacheHandler->delete($cache_key);