[Fire Android Development] Fahrenheit17:
Glorifyday,

You can't get points 3, 7, or 8 without root! SuperTool is unfortunately not very super anymore without root. The old version (for Fire OS 5.0.1) was very super even without rooting, but Amazon swiftly took care of that "problem"!

A. I've undone SuperTool changes, except I've never turned lock screen ads back on intentionally (only as part of a larger revert/reset).

B. You have 5.1.2.1. I just setup a late-2015 unit today and it OTA'd to that version (unfortunately). It does not show that last .1, but it's there!

C. I was able to load Google but NOTHING ELSE with the 5.1.2.1 update applied.

D. Not "if"…"when"! Turning off Wi-Fi isn't a solution because KingRoot requires an internet connection to do its work (they describe it as looking up a rooting strategy from the cloud). And until you've done the root, you can't block the OTA. The strategy I used (because I have a local DHCP/DNS server) was to create master zones for akamaihd.net, edgesuite.net, and amazon.com with glue records pointing to 10.99.99.99 (a bogus IP). I temporarily disabled IPv6 routing so I didn't have to worry about AAAA glue records. After I blocked OTA, I purged those zones and all was well. Assuming you probably don't have control of your DNS server, you could use content blocking/access control features in your router (if it provides them) or use OpenDNS (be sure to restart the Fire if it's already connected to Wi-Fi because it doesn't always purge its DNS cache, even when it gets new DHCP settings pointing it to a new DNS server) and block those domains (amazon.com, edgesuite.net, and akamaihd.net) from the OpenDNS control panel.

Where to get the 5.1.2 downgrade firmware file: http://xdaforums.com/amazon-fire/general/index-amazon-fire-2015-t3210485

Where I found the list of hostnames to block to temporarily prevent OTA: http://www.aftvnews.com/how-to-block-software-updates-on-the-amazon-fire-tv-or-fire-tv-stick/

One more IMPORTANT thing: You'll probably have to do KingRoot over and over at least 3-4 times (perhaps more) to get it to work. I finally got it to work after loading the (Chinese) desktop version of the app in Windows (had to find a Windows computer first) — the installer screens are all familiar, so you don't have to read Chinese to use it…truly! The desktop app failed, but the next attempt (4th overall) on the Fire made it work. I doubt the desktop app was necessary. Just keep doing it over and over on the Fire. If the tablet reboots in the process, that's a good sign, but doesn't mean that particular attempt will be successful. If it fails 2-3 times in a row without ever restarting in the process, that's probably NOT a good sign.

Good luck!

---------- Post added at 03:16 AM ---------- Previous post was at 03:09 AM ----------

The Chinese app came as a shock to me too, but ultimately it was trivial to figure out. The installer looked just like any other installer in any language. The app itself had only one button IIRC and it then failed to a giant icon of a cloud with an exclamation mark. HOWEVER, after that, the next attempt on the device itself worked!

---------- Post added at 03:20 AM ---------- Previous post was at 03:16 AM ----------

And if that fails (as indicated by a giant cloud with an exclamation mark and a lot of Chinese text), try it again on the device. For me, 3 fails on the device and 1 fail on the desktop led to a success on the device!