Unlocking Bootloader Moto G Unable to bootup
First download the corresponding firmware for your devices here.

Then follow (at your own risk) this updated guide.



I had the same problem with a Xperia M4 Aqua, and I couldn't override the 'OEM Allow Unlock' since phone wouldn't boot up.
I tried to perform the follwing in order to override that:

fastboot erase cache
fastboot erase userdata


It didn't work for me, but you can try on your phone, maybe you get lucky.

Since I was on Sony Xperia, I managed to flash a stock firmware using Sony Flashtool.