Kaltura_Client_Exception thrown

Invalid KS "MTlkMWM5MWE4YTgwY2ZjY2U2NTlmMjFmZGE0OWQ1ZDI0MmUxMDBiY3wxMDE7OzE0OTMyMDM3MDc7MjsxNDkzMTE3MzA3LjY0MzE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"