Unable to display pdf document with Traditional Chinese using Acrobat Reader

I got the following error:

The Traditional Chinese Language Support Package is required to display this page properly. Under the current configuration, this resource is not available. You can download it from http://www.adobe.com/go/acroasianfontpack

when opening this document:

http://www.hkssf-hk.org.hk/hk/pri/4_KW/4s_Prog_1011.pdf

I did not find any useful information on the Adobe website. Can anyone help on this ?

For your information, I can display Traditional Chinese web pages without any problem with Firefox.