[XT1058] Trying to flash stock firmware -> gpt.bin error and risk to brick

Hi, im having a unlocked xt1058, i just upgraded the phone to last 5.1 OTA, unlocked the BL and installed CM13 without problems at all, now after some researching ive noticed that my gps is bugged and im needing to get back to stock to make it work in CM13, everything cool at this point, just downloaded the latest firmware for my device on my cid and there's where problems started.

I've just downloaded XT1058_GHOST_RETAR_5.1_LPA23.12-15_cid12_CFC.xml from march of 2016, uncompress it on a fastboot folder that ive created for flashing purposes and started the flashing process.

First command i put into the fastboot is fastboot flash partition gpt.bin and the phone BL and fastboot returned to me errors.

From phone:
getvar has-slot:partition
getvar partition-type:partition
getvar max-download-size
downloading 32768 bytes
done
downgraded security version
update gpt_main version failed
preflash validation failed for GPT

From cmd:
target reported max download size of 805306368 bytes
sending 'partition' (32 KB)...
OKAY [ 0.247s]
writing 'partition'...
FAILED (remote failure)
finished. total time: 1.089s

I dont want to start test things without knowing it at all, is the first time im flashing a firmware to my moto x, all the other things ive done was under OTA automation, now im BL unlocked and i think i can mess the phone, can u help me please? ^^