If your recorder is an NVR8-8580 and for some reason, it fails to update over-the-air (OTA) to the latest Software Version of V8.1.0-20220418, here are the things you can do.

To check what is your current firmware, access the NVR's Menu then go to System > Information and look for the Software Version.

For units that have a Software version prior to V7.1.0-20180723, check this article to first as we need the NVR to be at this firmware before we start: How to do OTA update? Proceed below once you have this firmware.

1. Prepare a FAT32 flash drive or USB - it needs to be on FAT32 for it to be read; there is no need for an external HDD as the files are small.
2. Download the firmware files HERE, extract the files, and save it to your flash drive.
3. Unplug the Ethernet cable connected to the NVR then reboot.
4. Insert the flash drive into your NVR.
5. Access the Menu and go to Advanced > Maintain then click on Upgrade.
6. Select a file:
   1. For NVRs with firmware version V7.1.0-20180723, choose this file: N4XXX_V190321V180620V180620V200829V180723V180724.sw and click OK.
   2. For NVRs with firmware version V7.1.0-20180724, choose this file: N42XX_V190321V180620V190808V190810V190810V190810V190718.sw and click OK.
   3. For NVRs with firmware version V8.1.0-20190810 or newer, you may now follow this article: NVR8-8580 USB Firmware Update
7. A confirmation window will appear, click on OK again.
8. NVR will start to update. Make sure not to unplug the USB or turn off the NVR while it is updating.
9. Repeat steps 5 to 9 until you reach the latest firmware V8.1.0-20220418