Kaltura_Client_Exception thrown

Invalid KS "MmNiNjMxMzNlNGRiMzc1M2Y0OTZlMTk5YTQwMWE0MDRlYWNiYjhkNHwxMDE7OzE0OTM2MDI1ODM7MjsxNDkzNTE2MTgzLjI2NTg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"