A PHP Error was encountered

Severity: 8192

Message: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated

Filename: helpers/url_helper.php

Line Number: 535

Backtrace:

File: /home/pp21kk/domains/archiwum.pp21.kk.edu.pl/public_html/application/controllers/Sgg.php
Line: 11
Function: redirect

File: /home/pp21kk/domains/archiwum.pp21.kk.edu.pl/public_html/index.php
Line: 315
Function: require_once