Duplicate Maintenance Info
From Joomla! Documentation
Duplicate information shown in the Maintenance section in the Backend.
This pertains only to Joomla! version(s): 3.4.2 and 3.4.3
What is the cause
How to fix
Apply the patch https://github.com/joomla/joomla-cms/pull/7323.diff and clean your Browser and Joomla Cache.
This fix will be included in 3.4.4.