Kaltura_Client_Exception thrown

Invalid KS "MmYwMTJiMzIyN2NhZGZjYzE5YTk1OGI3ZDI3YTcxYmY3NjM5NjExY3wxMDE7OzE0NzU0MzYxODA7MjsxNDc1MzQ5NzgwLjM3MDM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"