CHANT has moved to a new URL and you probably tried to assess the database right at that time.
Now the link in CrossAsia is fixed and points to the new site. Because of changes in their login procedure users now have to click the 機構用戶登入-button to the right ("for IP users only"). Other updates and improvements are listed in their at the CHANT main page. Among other things a new 字庫 has to be downloaded and installed. Have fun!
Attached please find a screen shot of the login screen. If it does not load properly, please click again on 登入 on the menue. Success!