I deactivate this plugin and my site stopped working

@Juan: by "deactivating" do you mean you disabled the plugin in the plugin list on your site or do you mean you simply removed the plugin folder from the mod directory on your server? In case of the latter, the problem might be caused by the site cache not yet knowing that the plugin is missing. In this case, flush the cache. If you are unable to log in to your site to initiate the cache flushing on the admin section, you should execute the Elgg upgrade script by calling http://urlofyoursite/upgrade.php. This won't do any harm but it will also flush the cache of your site.

Hello, does it works with elgg 1.9 ?

@Marcuslutz the plugin has not been updated for 1.9 yet, but it also has not been tested to see if it works in 1.9... so feel free to test it and report back