Kaltura_Client_Exception thrown

Invalid KS "MzEwM2ExZGJjOWNkNGU2MzhiY2VjY2FmZTJkMzRmYWYyYjdkNmYwZXwxMDE7OzE0OTM2MDI5NTU7MjsxNDkzNTE2NTU1Ljg3MDk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"