explode(): Passing null to parameter #2 ($string) of type string is deprecated

line #     FECES_ERROR_HANDLER('8192','explode(): Passing null to parameter #2 ($string) of type string is deprecated','/home/puke7/botb/whats/entry/entry.php','45');

line #45     explode('x','');
/home/puke7/botb/whats/entry/entry.php

line #30     require_once('/home/puke7/botb/whats/entry/entry.php');
/home/puke7/botb/_FECES.php