Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /homepages/9/d331041642/htdocs/blkneu/aaakalender2.php:136 Stack trace: #0 /homepages/9/d331041642/htdocs/blkneu/aaakalender2.php(136): mysqli_num_rows(false) #1 /homepages/9/d331041642/htdocs/blkneu/kalender2.php(287): kalender_ausgabe->set_tblkalender(Object(mysqli), '2023') #2 {main} thrown in /homepages/9/d331041642/htdocs/blkneu/aaakalender2.php on line 136