1. Wrong IP address or port number of the device: Please check whether the IP address and port number of the device are correct, and ensure that the information entered is consistent with the actual IP address and port number of the device.
2. The user name or password of the device is incorrect: Please check whether the user name and password of the device are correct, and ensure that the information entered is consistent with the actual user name and password of the device.
3. The device is not online or does not support adding: Please check whether the device is online. If the device is not online, it cannot be added. In addition, some devices may not support adding to Hikvision's online device list.
4. The versions of the device and the client are incompatible: please check whether the versions of the device and the client are consistent. If the versions are not compatible, the device cannot be added.