Campaign Keyword was broken

I am using with Piwik 2.16.0

I set the campaign_var_name is “cc_cp”, campaign_keyword_var_name is “cc_kw” on my config.ini.php file.

when I test below url to my piwik server, but keyword displayed broken as “하프클럽”

http://mydomain.com/test.html?&cc_cp=neoclick_h&cc_kw=하프클럽&NCKWDM=����Ŭ��

cc_kw parameter is encoded by utf-8, when i decode as utf-8, it’s ok.
and, NCKWDM parameter, when i decode as utf-8, it’s broken like this &cc_kw=하프클럽&NCKWDM=����Ŭ��
but, i don’t care the NCKWDM parameter because i don’t use it in my piwik server

I tested again, without NCKWDM parameter, and NCKWDM parameter with correct encoded keyword,
yes, it’s ok. I can get correct keyword on my dashboard.

So, If there is a broken value of parameter on the url even though Piwik doesn’t use a parameter, the broken keyword is displayed on my dashboard.

Thanks for your help.