Hi Anuj,
When you open documents with CJK font in Adobe reader, the corresponding font files are not installed with adobe reader installation, so adobe reader asks to install the font packages separately . It is the default behavior in adobe reader. But in multilingual supported adobe reader is used to install font packages with installation, so document with CJK font can be easily opened in Multilingual supported reader, so we are suggesting you to use multilingual supported adobe reader or you can use latest adobe reader.
Please let me know if you need further assistance.
Regards,
Bhuvaneswari N.