Could not save data. Error: Could not write to the configuration file in Joomla. This is the error I faced while saving search engine friendly url for one of my joomla site. Though I have configured .htaccess I was not able to save . Every time I press save button this error come.Then I thought to check permission of configuration.php . The permission of that file was 444 it means Joomla wont be able to save settings. The I changed the permission of the file to 775 and above error went away. Yes , Now my site seo friendly url.