While the Zosi ZR08JP is a robust system, firmware issues can arise. Because Zosi uses various internal chipsets under the same model name, The "top" advice for this device is to always verify your Device Version in the System Info menu or contact Zosi Support directly with your Serial Number to get the precise file.
If your DVR is currently connected to the internet and functioning enough to access the menu:
Drop a comment on Zosi’s official YouTube channel or contact their Asia-Pacific support line. They provide direct firmware links for any ZR08JP user who provides their device’s serial number.
Plug your prepared USB drive into the NVR’s USB port.