Fatal error: Uncaught Error: Call to undefined function function_tool() in D:\wwwroot\changhan.com\ThinkPHP\ThinkPHP.php:15 Stack trace: #0 D:\wwwroot\changhan.com\index.php(5): require() #1 {main} thrown in D:\wwwroot\changhan.com\ThinkPHP\ThinkPHP.php on line 15