We have 2 Hikvision NVR's I am trying to connect to IVMS-4200. They were both connecting Monday and today, on one of the NVR's, nada. The ports are forwarding correctly, everything is setup properly on the NVR and in IVMS. I can connect to the NVR via IE but not through IVMS. The logs show a successful handshake on the NVR but then a reset packet is instantly sent after the connection. The firmware is up to date. No changes have been made to the Firewall, switches or to the NVR. Error Code 73 on iVMS-4200, installed locally.