Ultimate Facebook plugin .mo/ .po language translations.

I edited "wpmu-dev-facebook-default.po" file. Exported as "wpmu-dev-facebook-zh_TW.po" and "wpmu-dev-facebook-zh_TW.mo" file. Then i copied them to the plugin's language file. Nothing changed. How can i active my language file.

*My site justmakeapp.com is a network multisite. And I network activate the ultimate facebook.