Kaltura_Client_Exception thrown

Invalid KS "MDhiMGIwMDI5MzJhNDllMzExNGFiMmU5NjM3YjlkNzcwYTU1OWExOXwxMDE7OzE1MDEwMDAxNDE7MjsxNTAwOTEzNzQxLjQzNTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"