Fatal error: Uncaught Error: Call to undefined function exec() in C:\wwwroot\cdzszkj.com\include\chat.class.php:303 Stack trace: #0 C:\wwwroot\cdzszkj.com\chat.php(40): Chat->mac() #1 C:\wwwroot\cdzszkj.com\index.php(119): require('C:\\wwwroot\\cdzs...') #2 {main} thrown in C:\wwwroot\cdzszkj.com\include\chat.class.php on line 303