1. you need to open a mig33 lite version.then go to any friend of your friend list,then menu=>edit details=>=>mig33 user name(edit here)[username who u wanna start privet chat]=>ok.
2.then go to any room and click on privet chat and at the last on list enter username=>type the id who you wanna start privet chat.and this time u'll not get the same error.