Hi thanhv,
We haven’t had any other reports of this, but let’s get you sorted out here!
Did you experience any trouble during the update? Are you using any third-party add-ons that have to do with members or user data?
What version of PHP/MySQL is the server running?
Make a backup of /system/expressionengine/third_party, /system/expressionengine/config/config.php, /system/expressionengine/config/databse.php and /themes/third_party
Download a fresh copy of ExpressionEngine 2.4 and upload that to your sever.
Replace the the relevant folders and files with your backups.
Remove /system/installer/
Verify $system_path in index.php and admin.php
Try to reproduce the error.
What was the result?
I look forward to your response!
Cheers,