Fatal error on internet

[vasano]

This message appears in the internet:

Fatal error: Call to undefined function mb_internal_encoding() in /home/vyh0g9zp/public_html/a/core/init.php on line 21

What shall I do?

[fathira]

may be that server side jest contact  server support

[abantecart]

make sure mbstring PHP extension is installed on your server:

http://php.net/manual/en/mbstring.installation.php

You can check with your hosting so they enable it for you.