Kaltura_Client_Exception thrown

Invalid KS "MTNjOWFkNDFlY2FkODQxMDlmYjk4NzM4ODcxNWY4MzMzMjhjYzhjZXwxMDE7OzE1MDExNjc2NDk7MjsxNTAxMDgxMjQ5LjI5NTI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"