[软件故障] PHP Fatal error: Class 'Think\Log' not found的原因

PHP Warning:  include(D:\wwwroot\feifeicms\Lib\ThinkPHP\Library/Think/Log.class.php): failed to open stream: No such file or directory in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 152
PHP Warning:  include(): Failed opening 'D:\wwwroot\feifeicms\Lib\ThinkPHP\Library/Think/Log.class.php' for inclusion (include_path='.;C:\php\pear') in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 152
PHP Fatal error:  Class 'Think\Log' not found in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 336
PHP Warning:  include(D:\wwwroot\feifeicms\Lib\ThinkPHP\Library/Think/Log.class.php): failed to open stream: No such file or directory in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 152
PHP Warning:  include(): Failed opening 'D:\wwwroot\feifeicms\Lib\ThinkPHP\Library/Think/Log.class.php' for inclusion (include_path='.;C:\php\pear') in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 152
PHP Fatal error:  Class 'Think\Log' not found in D:\wwwroot\pc\Lib\ThinkPHP\Library\Think\Think.class.php on line 265