After Nx Witness upgrade to 3.1 version some Hikvision cameras might get offline.
It happens because since 3.1 Nx Witness has started to utilize Hikvision native ISAPI calls for some advanced configuration.
It has been noticed that Hikvision cameras with firmware 5.0.x or older often fail on such proprietary calls.
How to resolve the issue?
Just go ahead and upgrade your camera firmware.
Our tech team confirmed that even upgrade to 5.1.x is enough but we strongly recommend to keep your devices firmware up-to-date.
If you have any questions related to this topic or you want to share your experience with other community members or our team, please visit and engage in our support community or reach out to your local reseller.