Kaltura_Client_Exception thrown

Invalid KS "YzNhNzZjNjk3YjQzMDY3YTIzNjZiZmQ2MDQwNzEwZDI3NDMyZGFjOHwxMDE7OzE0NzUwNTQzMTg7MjsxNDc0OTY3OTE4LjcwNTY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"