NxWitness is one of those affected, but they have begun to address the issue in their latest patch release

The attached document from Hikvision shows the necessary steps to re-enable Onvif.

For NxWitness the "Enable Hikvision CGI" checkbox must also be ticked.

For the latest patch release of Nx, first enable Hik CGI as below - then add device to Nx.

Nx will create and enable the onvif user.

For the Nx stable release - on occasions the camera remains locked if Nx has auto-discovered the camera.
To fix this we use the following workaround;