Kaltura_Client_Exception thrown

Invalid KS "MTQyZjM4YTMxMDU1NTk4ZTdmNzcyZTcyZWIwZjQyNTc0YzUyNThjMnwxMDE7OzE0OTM0NjIwOTk7MjsxNDkzMzc1Njk5Ljc1Nzg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"