diff --git a/db/update12.4.2.sql b/db/update12.4.2.sql
index 2946802dcf..61fd2ece60 100644
--- a/db/update12.4.2.sql
+++ b/db/update12.4.2.sql
@@ -4,3 +4,4 @@ CREATE TABLE IF NOT EXISTS `zt_planstory` (
   `order` mediumint(9) NOT NULL,
   UNIQUE KEY `unique` (`plan`,`story`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+ALTER TABLE `zt_case` change `fromCaseVersion` `fromCaseVersion` mediumint(8) unsigned NOT NULL default '1' AFTER `fromCaseID`;
diff --git a/module/upgrade/model.php b/module/upgrade/model.php
index 2154e1e2ba..03ae09345b 100644
--- a/module/upgrade/model.php
+++ b/module/upgrade/model.php
@@ -613,6 +613,7 @@ class upgradeModel extends model
         case '12_4_2':
             $this->saveLogs('Execute 12_4_2');
             $this->execSQL($this->getUpgradeFile('12.4.2'));
+            $this->fixFromCaseVersion();
             $this->appendExec('12_4_2');
         }
 
@@ -3836,6 +3837,35 @@ class upgradeModel extends model
         return true;
     }
 
+    /**
+     * Fix fromCaseVersion field for zt_case table.
+     * 
+     * @access public
+     * @return bool
+     */
+    public function fixFromCaseVersion()
+    {
+        /* Get imported cases and cases version is null. */
+        $errorCasePairs = $this->dao->select('id,fromCaseID,fromCaseVersion')->from(TABLE_CASE)->where('fromCaseID')->ne(0)->andWhere('fromCaseVersion')->eq(0)->fetchPairs('id', 'fromCaseID');
+        $this->saveLogs($this->dao->get());
+        if(empty($errorCasePairs)) return true;
+
+        /* Get from case versions by from cases. */
+        $fromCaseIdList   = array_unique(array_values($errorCasePairs));
+        $fromCaseVersions = $this->dao->select('id,version')->from(TABLE_CASE)->where('id')->in($fromCaseIdList)->fetchPairs('id', 'version');
+        $this->saveLogs($this->dao->get());
+
+        /* Fix fromCaseVersion field. */
+        foreach($errorCasePairs as $caseID => $fromCaseID)
+        {
+            $fromCaseVersion = zget($fromCaseVersions, $fromCaseID, 1);
+            $this->dao->update(TABLE_CASE)->set('fromCaseVersion')->eq($fromCaseVersion)->where('id')->eq($caseID)->exec();
+            $this->saveLogs($this->dao->get());
+        }
+
+        return true;
+    }
+
     /**
      * Save Logs.
      *