Kaltura_Client_Exception thrown

Invalid KS "MWU4OTQwYTgxZjAyOGU3NTg3YTI3ZDY2YzdmN2U2M2QzNTkxZDY0NHwxMDE7OzE0OTgyMjEzOTc7MjsxNDk4MTM0OTk3Ljc4NjE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"