Hi,
This tool should help you, like it did to me, recover bluetooth modules RN4870, BM70, RN4871, BM71 which have a corrupted BTaddress or this message : %Unknown Device%
This tool is originally for the RN4870, BM70, RN4871, BM71 pictail boards but should be usable on other boards as well if a COM port is available through a USB to USART device/cable.
The SW package is located here : https://www.dropbox.com/sh/kpc3bkxcemb2 ... LAJGa?dl=0
I have been able to use it on Windows 10 Pro.
Regards