I can't unlock bootloader of my moto g xt1033 android 4.4.4 Guys I've been stuck at this step for a while. My device as Motorola says is unlockable and I also have the unlock code but still it says in the command window that error occurred. I've installed android SDK and in it I've installed the platform-tools and all the other build tools. 

Link  to screenshot:https://www.dropbox.com/s/wgqpq7jdki6sik5/Untitled.png
There is a bug in Android KitKat 4.4.4 which causes this issue. A thread in the motorola forum explains how to resolve the issue.

Follow these instructions only if you have upgraded to 4.4.4! If you have 4.4.3 or 4.4.2 it is more likely that you misspelled your unlock key.


Download the boot loader patch (this the link from the forum)
extract the ZIP file &amp; read instructions
your user data might be erased as part of this process
Then run following commands:

$ fastboot flash motoboot motoboot_41.15_testdrive.img
$ fastboot reboot-bootloader
... your device will reboot in fasboot mode

$ fastboot oem unlock [UNLOCK KEY]
... wait for unlock confirmation ...
... you might see some error messages here, ignore them...

$ fastboot flash motoboot motoboot.img
$ fastboot reboot