diff --git a/config/config.php b/config/config.php
index f2ca73b6db..f5d486673c 100644
--- a/config/config.php
+++ b/config/config.php
@@ -138,7 +138,7 @@ define('TABLE_ACTION',        '`' . $config->db->prefix . 'action`');
 define('TABLE_FILE',          '`' . $config->db->prefix . 'file`');
 define('TABLE_HISTORY',       '`' . $config->db->prefix . 'history`');
 define('TABLE_EXTENSION',     '`' . $config->db->prefix . 'extension`');
-define('TABLE_LANG',          '`' . $config->db->prefix . 'lang`');
+if(!defined('TABLE_LANG')) define('TABLE_LANG', '`' . $config->db->prefix . 'lang`');
 
 $config->objectTables['product']     = TABLE_PRODUCT;
 $config->objectTables['story']       = TABLE_STORY;
diff --git a/module/product/view/browse.html.php b/module/product/view/browse.html.php
index 83beb7babf..cfd30b5bf2 100644
--- a/module/product/view/browse.html.php
+++ b/module/product/view/browse.html.php
@@ -103,8 +103,8 @@
         <td class='text-left' title="<?php echo $story->title?>"><nobr><?php echo html::a($viewLink, $story->title);?></nobr></td>
         <td title="<?php echo $story->planTitle?>"><?php echo $story->planTitle;?></td>
         <td><?php echo $lang->story->sourceList[$story->source];?></td>
-        <td><?php echo $users[$story->openedBy];?></td>
-        <td><?php echo $users[$story->assignedTo];?></td>
+        <td><?php echo zget($users, $story->openedBy, $story->openedBy);?></td>
+        <td><?php echo zget($users, $story->assignedTo, $story->assignedTo);?></td>
         <td><?php echo $story->estimate;?></td>
         <td class='story-<?php echo $story->status;?>'><?php echo $lang->story->statusList[$story->status];?></td>
         <td><?php echo $lang->story->stageList[$story->stage];?></td>
diff --git a/module/project/view/task.html.php b/module/project/view/task.html.php
index 71b8b9b1f0..1098d71277 100644
--- a/module/project/view/task.html.php
+++ b/module/project/view/task.html.php
@@ -95,7 +95,7 @@
         <?php endif;?>
 
         <td <?php echo $class;?>><?php echo $task->assignedTo == 'closed' ? 'Closed' : $task->assignedToRealName;?></td>
-        <td><?php echo $users[$task->finishedBy];?></td>
+        <td><?php echo zget($users, $task->finishedBy, $task->finishedBy);?></td>
 
         <?php if($this->cookie->windowWidth > $this->config->wideSize):?>
         <td><?php echo substr($task->finishedDate, 5, 6);?></td>
diff --git a/module/project/view/view.html.php b/module/project/view/view.html.php
index c03de0978c..016e79696e 100644
--- a/module/project/view/view.html.php
+++ b/module/project/view/view.html.php
@@ -93,19 +93,19 @@
           </tr>
           <tr>
             <th><?php echo $lang->project->PM;?></th>
-            <td><?php echo $users[$project->PM];?></td>
+            <td><?php echo zget($users, $project->PM, $project->PM);?></td>
           </tr>
           <tr>
             <th><?php echo $lang->project->PO;?></th>
-            <td><?php echo $users[$project->PO];?></td>
+            <td><?php echo zget($users, $project->PO, $project->PO);?></td>
           </tr>
           <tr>
             <th><?php echo $lang->project->QD;?></th>
-            <td><?php echo $users[$project->QD];?></td>
+            <td><?php echo zget($users, $project->QD, $project->QD);?></td>
           </tr>
           <tr>
             <th><?php echo $lang->project->RD;?></th>
-            <td><?php echo $users[$project->RD];?></td>
+            <td><?php echo zget($users, $project->RD, $project->RD);?></td>
           </tr>
           <tr>
             <th><?php echo $lang->project->products;?></th>
diff --git a/module/task/view/view.html.php b/module/task/view/view.html.php
index e232544371..57906fb2c6 100644
--- a/module/task/view/view.html.php
+++ b/module/task/view/view.html.php
@@ -148,7 +148,7 @@
           </tr>
           <tr>
             <th><?php echo $lang->task->mailto;?></th>
-            <td><?php $mailto = explode(',', str_replace(' ', '', $task->mailto)); foreach($mailto as $account) echo ' ' . $users[$account]; ?></td>
+            <td><?php $mailto = explode(',', str_replace(' ', '', $task->mailto)); foreach($mailto as $account) echo ' ' . zget($users, $account, $account); ?></td>
           </tr>
         </table>
       </fieldset>
@@ -191,19 +191,19 @@
         <table class='table table-data table-condensed table-borderless'> 
           <tr>
             <th class='w-80px'><?php echo $lang->task->openedBy;?></th>
-            <td><?php if($task->openedBy) echo $users[$task->openedBy] . $lang->at . $task->openedDate;?></td>
+            <td><?php if($task->openedBy) echo zget($users, $task->openedBy, $task->openedBy) . $lang->at . $task->openedDate;?></td>
           </tr>
           <tr>
             <th><?php echo $lang->task->finishedBy;?></th>
-            <td><?php if($task->finishedBy) echo $users[$task->finishedBy] . $lang->at . $task->finishedDate;?></td>
+            <td><?php if($task->finishedBy) echo zget($users, $task->finishedBy, $task->finishedBy) . $lang->at . $task->finishedDate;?></td>
           </tr>
           <tr>
             <th><?php echo $lang->task->canceledBy;?></th>
-            <td><?php if($task->canceledBy) echo $users[$task->canceledBy] . $lang->at . $task->canceledDate;?></td>
+            <td><?php if($task->canceledBy) echo zget($users, $task->canceledBy, $task->canceledBy) . $lang->at . $task->canceledDate;?></td>
           </tr>
           <tr>
             <th><?php echo $lang->task->closedBy;?></th>
-            <td><?php if($task->closedBy) echo $users[$task->closedBy] . $lang->at . $task->closedDate;?></td>
+            <td><?php if($task->closedBy) echo zget($users, $task->closedBy, $task->closedBy) . $lang->at . $task->closedDate;?></td>
           </tr>
           <tr>
             <th><?php echo $lang->task->closedReason;?></th>
@@ -211,7 +211,7 @@
           </tr>
           <tr>
             <th><?php echo $lang->task->lastEdited;?></th>
-            <td><?php if($task->lastEditedBy) echo $users[$task->lastEditedBy] . $lang->at . $task->lastEditedDate;?></td>
+            <td><?php if($task->lastEditedBy) echo zget($users, $task->lastEditedBy, $task->lastEditedBy) . $lang->at . $task->lastEditedDate;?></td>
           </tr>
         </table>
       </fieldset>
diff --git a/module/user/model.php b/module/user/model.php
index 556b741a42..f9f2eba19b 100644
--- a/module/user/model.php
+++ b/module/user/model.php
@@ -619,6 +619,8 @@ class userModel extends model
     public function failPlus($account)
     {
         $user  = $this->dao->select('fails')->from(TABLE_USER)->where('account')->eq($account)->fetch();
+        if(empty($user)) return 0;
+
         $fails = $user->fails;
         $fails ++; 
         if($fails < $this->config->user->failTimes) 
@@ -645,6 +647,8 @@ class userModel extends model
     public function checkLocked($account)
     {
         $user = $this->dao->select('locked')->from(TABLE_USER)->where('account')->eq($account)->fetch(); 
+        if(empty($user)) return false;
+
         if((strtotime(date('Y-m-d H:i:s')) - strtotime($user->locked)) > $this->config->user->lockMinutes * 60) return false;
         return true;
     }