Fatal error: Uncaught TypeError: array_shift(): Argument #1 ($array) must be of type array, null given in C:\inetpub\wwwroot\2021\asyncexecutor-2021-06-08 (1)\examples\bg_process.php:4 Stack trace: #0 C:\inetpub\wwwroot\2021\asyncexecutor-2021-06-08 (1)\examples\bg_process.php(4): array_shift(NULL) #1 {main} thrown in C:\inetpub\wwwroot\2021\asyncexecutor-2021-06-08 (1)\examples\bg_process.php on line 4