iThemes Security makes significant changes to your database and other site files which can be problematic for existing WordPress sites. Do not attempt to add features that you’re not familiar with. We strongly recommended making a complete backup of your site before using this plugin.
While problems are rare, most support requests involve the failure to make a proper backup before installation.
Note: Renaming the wp-content directory will not update the path in existing content. Use this feature only on new sites or in a situation where you can easily update all existing links.