First of all, a greeting to all the users of the Forum. I have been following you for over a year and have 5 boxes with Arctic Fox installed. I state that I had successfully loaded Arctic Fox (200619 with NFE Tool 190718) on a Sinuous V80 (STM32) a few months ago and it worked perfectly. Since I got a second v80, also STM32, I wanted to do the same thing. And the problems began. After the firmware upload, the box went into safe mode, but it was no longer detected by Windows 10 (I tried on two PCs) and by NFE Tool. Since that time she is practically dead. I wanted to check with the first box, reinstalling Arctic Fox, but this too has turned off and is no longer detected by the PC (I followed the procedure suggested in Products Manual p.7.3). In short, now I find myself two boxes that make paperweights and I don't understand why. Do you think there may have been a hardware problem? I don't know what else to do.