diff --git a/CHANGES.rst b/CHANGES.rst
index d43906e0..204148c3 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -11,7 +11,8 @@ New:
 
 Fixes:
 
-- *add item here*
+- Fixed error message displaying during rearranging.
+  [Gagaro]
 
 
 3.0.14 (2015-11-26)
diff --git a/plone/app/content/browser/contents/__init__.py b/plone/app/content/browser/contents/__init__.py
index e89fd471..17016033 100644
--- a/plone/app/content/browser/contents/__init__.py
+++ b/plone/app/content/browser/contents/__init__.py
@@ -121,9 +121,9 @@ def message(self, missing=[]):
             translated_errors = [
                 translate(error, context=self.request) for error in self.errors
             ]
-            translated_msg = '{0:s}: {0:s}'.format(
+            translated_msg = u'{0:s}: {1:s}'.format(
                 translated_msg,
-                '\n'.join(translated_errors)
+                u'\n'.join(translated_errors)
             )
 
         return self.json({