Kaltura_Client_Exception thrown

Invalid KS "MmJiZDM0ZjFmN2EzYjA2Y2E1MTMwM2FmODNjMzBkZjJjM2Q2NDEyMHwxMDE7OzE1MDA3MDUwNDI7MjsxNTAwNjE4NjQyLjE3MTY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"