致命错误：未捕获错误：在bool

Question

  

致命错误：未捕获错误：调用成员函数bind_param（）   进来   C：\ xampp \ htdocs \ Project \ charity2 \ controllers \ authController.php：95   堆栈跟踪：＃0 C：\ xampp \ htdocs \ Project \ charity2 \ register.php（1）：   抛出require_once（）＃1 {main}   C：\ xampp \ htdocs \ Project \ charity2 \ controllers \ authController.php在   第95行

$sql = "INSERT INTO users (fname, lname, username, email, phone, verified, token, password) VALUES (?, ?, ?, ?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param('sssssbss', $fname, $lname, $username, $email, $phone, $verified, $token, $password);

if($stmt->execute()){