Before, I used CodeStyling Localization for my translations, but sometimes CSL don’t detect plugins or child-themes and CSL long time ago not receive updates and the developer of CSL don’t respond in the support forum.
So I decided to look for a new translation plugin and found Loco Translate.
When you create a new translation with Loco Translate lets you choose where to locate translation files. If you choose the folder /wp-content/languages/plugins instead of /wp-content/plugins/plugin_name/languages, ??iThemes Security be translated!
The problem is that iThemes Security will stop working properly, only work correctly the Dashboard section, the remaining sections of the plugin will stop working (you will see only white screen).
iThemes Security, is one of the best plugins for WordPress, is a real shame that the plugin of these errors with the translations.