I am having the same problem.
The Mooshimeter worked just fine since I bought it, but it recently wanted to do a firmware update.
Now it is in an endless loop, it never returns to the operating mode.
Says Meter disconnected”, then it goes back to page that says “Bootloader Invalid firmware”
I wish I saw MrPeak’s post a week ago :)
I guess I’ll need to send Mooshi an e-mail.