Kaltura_Client_Exception thrown

Invalid KS "MDk2YzNhZDk3YzM3NzQ1ODQ4YzcxN2JhNGI5ZjA3YmU0MjI5MGUwZXwxMDE7OzE0NzUwMjM0MzY7MjsxNDc0OTM3MDM2LjU5NjE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"