You will have to add the device once again and you will be prompted to assign a password. If you have any other issues with the application, then I recommend contacting the developers of the application using the following email: support@hikvision.com
Secondly, the password is generated by the application when you connect, but if you keep having issues with registration, simply reset the DVR device. You will have to remote administrate it or go to its location to access the security protocols to reset it or change the password.
