Kaltura_Client_Exception thrown

Invalid KS "MTdjMjM0NWI0M2Q2MjQ2MjY0ZWViZTlhODM3MDk0ZGRjM2RhYThiMnwxMDE7OzE0NzQ4MzgwNTg7MjsxNDc0NzUxNjU4LjEyMjM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"