Kaltura_Client_Exception thrown

Invalid KS "YzU0NDlkMTg2NDhmMDliZjNlNjE0Y2Y3Nzc1ODU2Njg3M2I2MDI5MXwxMDE7OzE1MDA5OTM1ODY7MjsxNTAwOTA3MTg2Ljk4NTI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"