Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /customers/9/9/e/lenigengezwind.be/httpd.www/Kaartjes_maken.php:7
Stack trace:
#0 /customers/9/9/e/lenigengezwind.be/httpd.www/Kaartjes_maken.php(7): mysqli_num_rows(false)
#1 {main}
  thrown in /customers/9/9/e/lenigengezwind.be/httpd.www/Kaartjes_maken.php on line 7