try to add Robot.txt from admin

edit

I get this error when trying to add robots from admin * to /*

MessageFailure at /admin/robots/rule/add/
You cannot add messages without installing django.contrib.messages.middleware.MessageMiddleware
Request Method: POST
Request URL:    http://admin/robots/rule/add/
Django Version: 1.4.3
Exception Type: MessageFailure
Exception Value:    
You cannot add messages without installing django.contrib.messages.middleware.MessageMiddleware
Exception Location: /usr/lib/python2.6/site-packages/Django-1.4.3-py2.6.egg/django/contrib/messages/api.py in add_message, line 22
Python Executable:  /usr/bin/python
Python Version: 2.6.6

How to solve this ?