Security issues with file mf_extra.php

I’m running wordpress 4.0 and Magic Fields 2.3.1. Everything worked fine, but now on my website this line of code appears
Warning: php_uname () has been disabled for security Reasons in /home/designi1/public_html/wp-content/plugins/magic-fields-2/mf_extra.php on line 39
Does anyone have any idea why this happens?
My website is http://www.designio.cl
The same is true with http://www.designio.cl/consejo/
Thank!

https://wordpress.org/plugins/magic-fields-2/