Kaltura_Client_Exception thrown

Invalid KS "MmZlYWUxOTllMmQ1ZTFkN2RmMTRkNTI1M2M1YmJiNWI3ODc0NTRjZHwxMDE7OzE0OTMxMTk1MDc7MjsxNDkzMDMzMTA3LjQzMDg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"