Hi,
got the same error few days ago. To fix it I used null-modem cable (female/female) RS-232, USB-to-RS232(male) cable, TFTP server from HikVision, NCOM v1.02 app. To interrupt boot you need to press * 3 times in NCOM console, then cnahge TFTP server IP address in NVR if necessary local NVR ip...