Firmware update doesn't start to install
I try to install the latest firmware on my JY-UO128N4G device, but it doesn't start, no matter if I use the integrated USB cable or the SD card slot.

I downloaded and unzipped the firmware and copied the files to USB and SD card and when I put one in, it says "external storage is installed" or something similar and then nothing happens.

In the file manager I can see the files, but that's it.

There are somehow too few files in the package as well.
For me it seems it is missing something.

Also there is no manual update, at least I couldn't find one.
So what do I do now?
Ok I was able to update the unit by making a factory reset while the firmware update was in the SD card slot.