Kaltura_Client_Exception thrown

Invalid KS "MzBkMWZkYjAzN2M3NDRkNjYyMGExMGYyNjlmN2FlZGI0ZTQxM2U4NnwxMDE7OzE0OTA2NjM0NDk7MjsxNDkwNTc3MDQ5LjczNTU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"