The latest software update, version 18.104.22.168, has blocked rooting using KingRoot, but Fire TV 2 owners wishing to root are in luck because the update has not blocked rbox’s rooting method. You can find my guide for how to root the Fire TV 2 using rbox’s method here. It works on 22.214.171.124 without any modifications. Big thanks to roligov for risking his Fire TV to discover that this method still works. Rest assured that I’ve personally tested the rooting method on a stock 126.96.36.199 Fire TV 2 that had never been rooted and everything went smoothly.
Rooting your Fire TV 2 with this method right now will result in you downgrading to software version 5.0.5 since a pre-rooted ROM for 188.8.131.52 has not been released yet. I have captured the update package for 184.108.40.206 and have passed it along to rbox, so a 220.127.116.11 pre-rooted ROM will probably be released soon. If you’re on 18.104.22.168, you can either block software updates and wait for the pre-rooted 22.214.171.124 ROM to be released before rooting, or root now with the 5.0.5 pre-rooted ROM and update to the 126.96.36.199 pre-rooted ROM when it’s released. Both options are safe to do.
As a reminder, this is the rooting method that requires an A-to-A USB cable, which most people do not have laying around. If you were considering taking advantage of the current Fire TV 2 sale, you can rest assured that rooting is still possible if you receive a device with 188.8.131.52 pre-installed, or can’t get through the intial setup process without updating.