Steps to reproduce the issue
Go to the main administrator page
Look at the left bottom messages for Maintenance Joomla and Extnesions they are shown twice.
Expected result
One message for Joomla and one for extensions.
Actual result
System information (as much as possible)
Additional comments
Clean your Browser cache it is a know issue see: https://docs.joomla.org/J3.x:Duplicate_Maintenance_Info