Kaltura_Client_Exception thrown

Invalid KS "MTljMjI1YWU2Y2I4NjMzN2E2ZDJkNmI2ZDRlNzhmZmU4NjA2ZmNjYXwxMDE7OzE0NzQ5NDgxNDY7MjsxNDc0ODYxNzQ2LjY3MTE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"