Fatal error: Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\forum\libraries\Database.php:31 Stack trace: #0 C:\xampp\htdocs\forum\libraries\Topic.php(26): Database->query('select * from t...') #1 C:\xampp\htdocs\forum\topics.php(18): Topic->getTotalTopics() #2 {main} thrown in C:\xampp\htdocs\forum\libraries\Database.php on line 31