Kaltura_Client_Exception thrown

Invalid KS "NmNjMTRhNTlmNWE5NDI2ZDRiOTc1ZTk2NjVmN2UzMmYzOWFiYTcwYXwxMDE7OzE0ODE0MTkyNTA7MjsxNDgxMzMyODUwLjQ2NTI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"