Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /home/aldaawaprivatealwasta.com/www/web/pages/register_student.php:155 Stack trace: #0 /home/aldaawaprivatealwasta.com/www/web/pages/register_student.php(155): mysqli_query() #1 /home/aldaawaprivatealwasta.com/www/modules.php(144): include('...') #2 /home/aldaawaprivatealwasta.com/www/index.php(337): include('...') #3 /home/aldaawaprivatealwasta.com/www/index.php(473): get_include_contents() #4 {main} thrown in /home/aldaawaprivatealwasta.com/www/web/pages/register_student.php on line 155