Fatal error: Uncaught TypeError: ksort(): Argument #1 ($array) must be of type array, null given in /www/wwwroot/testing.nanoa.cn/component/heepay/join.change.php:31 Stack trace: #0 /www/wwwroot/testing.nanoa.cn/component/heepay/join.change.php(31): ksort() #1 {main} thrown in /www/wwwroot/testing.nanoa.cn/component/heepay/join.change.php on line 31