解决办法：

打开include/userlogin.class.php

找到

1. function exitUser() 
2.     { 
3.         ClearMyAddon(); 
4.         @session_unregister($this->keepUserIDTag); 
5.         @session_unregister($this->keepUserTypeTag); 
6.         @session_unregister($this->keepUserChannelTag); 
7.         @session_unregister($this->keepUserNameTag); 
8.         @session_unregister($this->keepUserPurviewTag); 
9.         DropCookie('dedeAdmindir'); 
10.         DropCookie('DedeUserID'); 
11.         DropCookie('DedeLoginTime'); 
12.         $_SESSION = array(); 
13.     } 

替换为：

1. function exitUser() 
2.     { 
3.         ClearMyAddon(); 
4.         #@session_unregister($this->keepUserIDTag);         
5.         $_SESSION[$this->keepUserIDTag] = $this->userID; 
6.         #@session_unregister($this->keepUserTypeTag);         
7.         $_SESSION[$this->keepUserTypeTag] = $this->userType; 
8.         #@session_unregister($this->keepUserChannelTag);         
9.         $_SESSION[$this->keepUserChannelTag] = $this->userChannel; 
10.         #@session_unregister($this->keepUserNameTag);         
11.         $_SESSION[$this->keepUserNameTag] = $this->userName; 
12.         #@session_unregister($this->keepUserPurviewTag);         
13.         $_SESSION[$this->keepUserPurviewTag] = $this->userPurview; 
14.         DropCookie('dedeAdmindir'); 
15.         DropCookie('DedeUserID'); 
16.         DropCookie('DedeLoginTime'); 
17.         $_SESSION = array(); 
18.     }