Do you have a branded (Cotier) or unbranded mini NVR? In case of unbranded: Did you try the recovery file method located at the following site: http://www.urcctvstore.com/Download.html ?
Recovery File (for N6200-4E/8E,N6200-4EL/8EL,6100-4EP/8EP,N6100-4EP,8EP)
DownloadHow to Use Rebooting tools
Put the 4 recovery files + the firmware update 20150124 on a USB flashdrive and flash it again?
mine is noname cheapie from aliexpress with hi3520chip. i made telnet recovery. got earlie 20140416 version, the directly upgraded to 20141030. now it works fine.
but with some cams i can sea red ! in triangle="Video Exception" but i think i know why
thanks pals.