Is your server hosting SocialEngine running PHP 5.6? You may see the following error

“Use of iconv.input_encoding is deprecated”

When a user tries to login

Such deprecated warnings are being thrown because of PHP’s latest version on your server. So, please check doing below changes in "/application/index.php" file and that will resolve this issue on your website:

Please search for below code:

error_reporting(E_ALL);

and replace the above code with below one:

error_reporting(E_ALL ^ E_DEPRECATED);

I Believe this will fix the problem you are facing and it should be fixed officially within the next version as the site needs to keep up with PHP Versions

 Looking for quality SocialEngine Hosting? Look no further than Arvixe Web Hosting