I can finally activate the plugin, after I signin and create a playlist. I add widget to side page, It asked me to sign in, I signed in, but it point me to this directory:
http://harrytng.ipage.com/wp-admin//austinvietradiowidgets.php
"Page not found" of course, because I don't have this directory. You see the two forward slash "//" between wp-admin//austinvietradiowidgets.php. I think it's the code issue. Please check. Thanks.