Warning / Errors

Hi I´m have this two Warning / Errors collected by Code Pinch

Warning: array_unshift() expects parameter 1 to be array, null given
wp-includes/class-wp-xmlrpc-server.php 596 2016-10-20 12:46:31 (1)

Fatal Error: Maximum execution time of 30 seconds exceeded
wp-content/plugins/sucuri-scanner/sucuri.php 4657 2016-10-24 12:24:02 (1)

Is there anything I can do to change this, maybe is a missconfiguration stuff
Just wanna know is a big deal

Thank U!