diff --git a/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/Workflow_statusModify.xml b/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/Workflow_statusModify.xml
index 8fb7f6ae2766de4c7dff52c14f340498ef514283..26a9c4d400a5c5b7f9cd0352d946a8e571a7feb2 100644
--- a/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/Workflow_statusModify.xml
+++ b/product/ERP5/bootstrap/erp5_xhtml_style/SkinTemplateItem/portal_skins/erp5_xhtml_style/Workflow_statusModify.xml
@@ -52,6 +52,7 @@
             <key> <string>_body</string> </key>
             <value> <string encoding="cdata"><![CDATA[
 
+from Products.CMFCore.WorkflowCore import WorkflowException\n
 from Products.Formulator.Errors import FormValidationError\n
 from Products.DCWorkflow.DCWorkflow import ValidationFailed\n
 from Products.ERP5Type.Message import translateString\n
@@ -118,6 +119,12 @@ except ValidationFailed, error_message:\n
                           # that would become an error.\n
     log("Status message has been truncated")\n
     message = "%s ..." % message[:(2000 - 4)]\n
+except WorkflowException, error_message:\n
+  if str(error_message) == "No workflow provides the \'${action_id}\' action.":\n
+    message = translateString("Workflow state may have been updated by other user. Please try again.")\n
+    return context.Base_redirect(form_id, keep_items={\'portal_status_message\': message}, **kw)\n
+  else:\n
+    raise\n
 else:\n
   message = request.get(\'portal_status_message\')\n
   if message is None:\n
diff --git a/product/ERP5/bootstrap/erp5_xhtml_style/bt/change_log b/product/ERP5/bootstrap/erp5_xhtml_style/bt/change_log
index cdde4dc95cde437cee70e80d62c6e86d12338847..5adc017b09bd9c945b14934f726db970c19c1c34 100644
--- a/product/ERP5/bootstrap/erp5_xhtml_style/bt/change_log
+++ b/product/ERP5/bootstrap/erp5_xhtml_style/bt/change_log
@@ -1,3 +1,6 @@
+2012-10-16 yusei
+* Improve error handling on Workflow_statusModify. If requested transition is not available, then show a nice message.
+
 2012-9-12 yusei
 * Improve listbox sort feature. Now both ascending arrow and descending arrow are displayed in title column and user can sort in specific order explicitly. User also can sort multiple columns by click without using sort-on-dialog.
 
diff --git a/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision b/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
index e50f8eba35c7106e6174bc966bc996385de98272..8b37c8cfe6af5c68d4fa42f58ec2e3902cb94fdd 100644
--- a/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
+++ b/product/ERP5/bootstrap/erp5_xhtml_style/bt/revision
@@ -1 +1 @@
-1096
\ No newline at end of file
+1097
\ No newline at end of file