Kaltura_Client_Exception thrown

Invalid KS "MzVjMmU1NzY5Nzk3YTE2NjBiY2I2OGJiNjdmMGEzNzA1MzgzZGMyN3wxMDE7OzE0NzUwNjY4MjA7MjsxNDc0OTgwNDIwLjA5MDk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"