Kaltura_Client_Exception thrown

Invalid KS "MjNjNDE3ZjQzNWMyYzQ1MWM5YzE2MzA1YTQ2NGI2YWRiMWZlMTBmMXwxMDE7OzE0OTgzMjY0OTI7MjsxNDk4MjQwMDkyLjI1MDY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"