Got a VZW PRIV (now using with T-Mobile AT) donated when I was in Ontario and now trying to update to MM.
The PC recognizes the device OK but when in the "bootloader menu" (purple LED), I have no connection to the Windows PC anymore.
Then I select "3 - reboot into fastboot" and the screen goes blank for a second, and then I am back in the same menu (should it do that?)
Anyway, the flashall.bat file (started as admin) exits with hlos-sig-tag:=.
It does that also without USB cable attached, so obviously I am missing something I can do to get/stay connected during the process.