A PHP Error was encountered

Severity: 8192

Message: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated

Filename: controllers/Viewcaptcha.php

Line Number: 16

Backtrace:

File: /var/www/vhosts/bilalico.com/httpdocs/application/controllers/Viewcaptcha.php
Line: 16
Function: unserialize

File: /var/www/vhosts/bilalico.com/httpdocs/index.php
Line: 318
Function: require_once