When installing the updates to Joomla 3.4.x you may get a popup dialog box message indicating an "Invalid Login". After clicking the OK button the update process will appear as if it is still updating but the progress bar will not move. In this case the update has failed and no change was made to the system.
We found a number of reports of this issue and what we found was that it is most likely a permissions issue on the folder structure where Joomla is installed. By resetting the folder and file permissions so that the web server had complete control of everything, the update competed normally.
Each time Fedora would release a new version I would install a fresh install of the latest version. The difficulty was always trying to remember how I setup the previous system so that everything would work. In this case the primary function of the Fedor server was for web site hosting. These are the typical steps I used to create my Linux server based on research from others that have posted their process as well as my own experience in the process.
One additional aspect of this process was to support Joomla installations. You will note specific configuration settings that relate to the operation of Joomla in Linux at the end.