A PHP Error was encountered

Severity: Warning

Message: foreach() argument must be of type array|object, null given

Filename: z/main.html

Line Number: 56

Backtrace:

File: /var/www/project/p_paper2u/app/views/page/z/main.html
Line: 56
Function: _error_handler

File: /var/www/project/p_paper2u/app/controllers/Main.php
Line: 55
Function: view

File: /var/www/project/p_paper2u/index.php
Line: 315
Function: require_once