[Moto X General] KidJoe:
This is a reserection of -> http://xdaforums.com/moto-x/general/faq-kit-kat-how-to-prepare-carriers-t2536735 and -> http://mark.cdmaforums.com/MotoX-OTA.html

With Verizon pushing a maintenance release for their Stock 4.4.4 (which doesn't change the Android version number), I wanted to post this sooner rather than later because questions are coming up....

Whenever a new OTA comes up, there are always questions like "what do I need to do to take the OTA?" or "I got prompted to take the OTA, but xxx is happening." This thread is intended to provide that information in once place.

This information is based on the past OTA updates for the Verizon, T-Mobile, and ATT Moto X phones, and threads on various forums. It should apply to all OTA updates.

Please note: If you have tried downgrading by flashing only parts of a rom, or have mismatched files on your phone for any reason, DO NOT TAKE AN OTA or you will likely brick your phone!! First flash your phone with a full SBF of the latest ROM for your carrier before attempting to take future OTA's. For more on Downgrading and the risks associated with it, see -> [INFO/WARNING]The Risks of Downgrading, and the impacts of GPT.BIN and MOTOBOOT.IMG

These are the most common Questions and Issues we've seen in the past...

If you could NOT get your bootloader unlock code directly from Motorola and rooted by some other process, you should *WAIT* on taking an OTA update as it may patch any vulnerability being exploited to root your phone. And you may not be able to ROOT on this new version!!

If you used Sunshine, or got your Bootloader Unlock code from the China Seller or Middleman... You should BE CAUTIOUS and *WAIT* on upgrading past 4.4.4. Please see -> [LOLLIPOP WARNING]Those Who Unlocked Via Sunshine or Purchasing a Code from China

You should expect to lose root when you take an OTA.

For the Motorola X, the OTA's are incremental updates. You must be on a specific previous ROM, and "step up." To put it another way... To take the 4.4.4 OTA, your phone needs to be on 4.4.2 (or 4.4.3 depending on your model/carrier). To take the 4.4.2 OTA, your phone needs to be on 4.4. To take the 4.4 OTA, your phone needs to be on the 4.2.2 w/camera fix version. To take the 4.2.2 w/camera fix OTA, your phone needs to be on the initial shipping ROM version.

Inside the OTA is a "Pre-flash Validation Check" to ensure your phone is on the correct version BEFORE it will flash. It includes a manifest file that contains a list of files and their check sums the OTA expects to be on your phone. If the files are missing from your phone, or the check sum for a particular file doesn't match (because you've replaced or altered the file), the OTA will fall. NOTE: The more files patched by the update, the more strict the pre-flash validation will be. So an update from 4.4.4 -> 5.1 will be more strict than the recent Verizon 4.4.4 maintenance patch.

Because of #5, you must be "stock." Any bloat you deleted, needs to be put back. Any apps you froze with Titanium Backup or the like, may need to be unfrozen. Apps disabled via the phone's Settings -> Applications -> [select app] -> [disable] can remain disabled and should not impact the update. NOTE: Back in the "early days" of the 2013 X, all apps frozen with TiBu had to be unfrozen. Later updates that hasn't been much of a problem. I don't use it, so I can't say for sure.

If you have XPosed installed on your phone, it often does make changes that will cause the Pre-Flash Validation to fail. You may be able to just disable it, rather than fully removing it, and then take the OTA. (To disable Xposed, boot to TWRP and install /SDcard/Android/data/de.robv.android.xposed.installer/files/Xposed-Disable-Recovery.zip ) NOTE: There is a newer version of Xposed needed for Lollipop!!

The OTA Updates will only install via Stock Recovery. If your Root method has replaced stock recovery with something else, you will need to use mfastboot to flash stock recovery on your phone BEFORE you attempt to take the update. Not having Stock Recovery on your phone when you take the OTA can result in your phone doing a boot loop. NOTE: You can use fastboot erase cache to delete the update zip file from your phone which will stop the boot loop.

There are several options to get back to "stock" without loosing your data. (I will add them to Post #2 of this thread at a later date), some are more technical, some are more noob friendly. The one you use, depends on how much, or how little, you have modified your phone away from stock.

In some cases, using mfastboot to reflash stock Recovery.IMG and System.IMG can be enough to get you back to "Stock" and take the OTA update.

If you unlocked your bootload by getting the code from Moto, after taking the OTA you may root by following -> http://xdaforums.com/moto-x/moto-x-qa/instructions-unlocking-rooting-dev-ed-t2649738 Please be sure to use the latest TWRP fastboot IMG file (Alternate Link) and Installable ZIP of SuperSU

Any tethering hacks you have done will likely need to be undone in order to take the OTA (see #5 above), and may not work after the OTA is installed.

Some FAQ's...

I've tried taking the OTA, but I'm stuck in a loop. It wants to keep rebooting. - This is usually caused by having a 3rd party recovery, like TWRP/CWM, on the phone. Re-flash the stock recovery to install the OTA update, or use fastboot erase cache to delete the update zip file from your phone which will stop the boot loop. (instructions will be added to Post #2 of this thread in the future)

I've tried putting back my bloat, and taking the OTA, but it fails. - You likely missed something the Pre-flash Validation check is looking for. If you are able to capture the OTA ZIP and use the SIDE LOAD AN OTA instructions (which will be added to post #2 of this thread in the future), you can watch progress of the OTA install. It will tell you the error, and/or what file doesn't match.

In the past we've seen error codes 252 and 410. These have been related to files on the phone not matching the OTA's pre-flash validation checks.