安裝dedecms后后臺登錄界面顯示空白怎么辦

1?if?(!isset($_SESSION[$this->keepUserIDTag])) ?2?//@session_register($this->keepUserIDTag);???? ?3?$_SESSION[$this->keepUserIDTag]?=?$this->userID; ?4? ?5?if?(!isset($_SESSION[$this->keepUserTypeTag])) ?6?//@session_register($this->keepUserTypeTag); ?7?$_SESSION[$this->keepUserTypeTag]?=?$this->userType; ?8? ?9?if?(!isset($_SESSION[$this->keepUserChannelTag])) 10?//@session_register($this->keepUserChannelTag); 11?$_SESSION[$this->keepUserChannelTag]?=?$this->userChannel; 12? 13?if?(!isset($_SESSION[$this->keepUserNameTag])) 14?//@session_register($this->keepUserNameTag); 15?$_SESSION[$this->keepUserNameTag]?=?$this->userName; 16? 17?if?(!isset($_SESSION[$this->keepUserPurviewTag])) 18?//@session_register($this->keepUserPurviewTag); 19?$_SESSION[$this->keepUserPurviewTag]?=?$this->userPurview; 20? 21?if?(!isset($_SESSION[$this->keepAdminStyleTag])) 22?//@session_register($this->keepAdminStyleTag); 23?$_SESSION[$this->keepAdminStyleTag]?=?$adminstyle;