windows环境，系统重启后禅道访问空白页！！ 悬赏5积分

windows2008+ZenTaoPMS.5.0.beta2，之前使用正常，昨天机器重启后，启动禅道服务提示正常，但是，访问禅道出现空白页。查看了xampp\zentao\tmp\log\下的日志文件，内容如下：

09:50:48 ERROR: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) in D:\xampp\zentao\framework\router.class.php on line 1533, last called by D:\xampp\zentao\framework\router.class.php on line 1495 through function connectByPDO.
 in D:\xampp\zentao\framework\router.class.php on line 1576 when visiting 

09:50:51 ERROR: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) in D:\xampp\zentao\framework\router.class.php on line 1533, last called by D:\xampp\zentao\framework\router.class.php on line 1495 through function connectByPDO.
 in D:\xampp\zentao\framework\router.class.php on line 1576 when visiting 

09:50:59 ERROR: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) in D:\xampp\zentao\framework\router.class.php on line 1533, last called by D:\xampp\zentao\framework\router.class.php on line 1495 through function connectByPDO.
 in D:\xampp\zentao\framework\router.class.php on line 1576 when visiting 

09:51:03 ERROR: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) in D:\xampp\zentao\framework\router.class.php on line 1533, last called by D:\xampp\zentao\framework\router.class.php on line 1495 through function connectByPDO.
 in D:\xampp\zentao\framework\router.class.php on line 1576 when visiting

请问这是什么问题？如何解决？