Hello,
Today 11/12/2011 1am GMT+8 we are starting the first phase of data migration to season 6 database.
We will update this thread with our progress report.
The downtime could take 24 - 48 hours.
For now please download new Season 6 client here:
http://www.muonline.biz/zhyper/showthread.php?t=114203
You must uninstall / remove the old Season 5 client then install this new Season 6 client.
Thanks!