Check virtualhost configuration file. Use the below nginx recommended configuration as base https://www.nginx.com/resources/wiki/start/topics/recipes/drupal/
CKEditor does not work in Drupal 7. And you receive the below error when clicking on Configuration in CKEditor. To resolve the issue, download the latest CKEditor from http://ckeditor.com/download , unzip and copy the ckeditor folder into /sites/all/modules/ckeditor folder.
You are logged into a web site running on Drupal 7 however unable to logout. Using a direct link in the form of a clean URL works (http://sitename.com/user/logout). This is an issue with clean URL setting in Drupal.