[Upgrading, Modifying and Unlocking] kaliusscripts:
I found an unofficial method I've seen several times for multiple devices it's not my post.. All respects go to "Mexirony" I see him time to time on this subject...

I haven't been able to find a viable method to root the ZTE Majesty Pro (Z799VL) neither the ZTE Majesty Pro Plus (Z899VL). Factory-locked fastboot seems to be the eternal source of the problem. Decided to share with you guys a quick manual I made for the occasion to, at least, be able to debloat the device and make it run smoothly, while a smart soul of yours finds out a viable root technique. The method is valid for both devices and it is supported in long extent by the app "Ice Box". It is also valid only for Android 5+ or higher. If you got Android 4- or lower you may want to use Debloater instead.

NOTE*: I'm not responsible for soft-bricking the device if you don't follow to the word the instructions provided and educate yourself in the overall competences and crafts of Android services. If by mistake you fall in soft-bricking, simply do a hard reset, wipe data to factory settings and start all over again from the scratch. In that case, review this link

0.- VERY IMPORTANT: Backup all your data, contacts, phone numbers, calendar, agenda, photos, videos, bookmarks, notes, Whatsapp media, Facebook downloads, useful cache, personal information, etc., etc., all out from your handheld device.

1.- Install "Minimal ADB And Fastboot" software in your PC from here.

2.- Install "Ice Box Pro" - not free but the pro - version in your smartphone, either directly from Google Play ($1.99) or download somewhere in the Internet searching the criteria "ice box apk download". Navigate to "Settings -> Security". Check the option "Unknown sources". Tap "OK" on the prompt message, then select "Trust".

3.- Activate "Settings -> Developer options -> USB debugging" in Android Settings. If you don't know how to launch the "Developer" tab read this.

4.- Go to "Settings -> Accounts", then remove ALL ACCOUNTS including your Google, Skype, Hotmail, Netflix, Facebook, etc., etc. Later on you will set back on track all your personal accounts to normal.

5.- Multi-user or guest mode needs to be dismissed as well if has been set on your device (typically not the case). Check the status in "Settings -> Security -> Device Administrators".

6.- Connect your phone to your PC via USB-micro-USB cable. Make sure you have the USB drivers of the cellphone properly installed in your PC for Windows to recognize the dispositive. If not the case, download Android USB drivers here and try again.

8.- Run the "Minimal ADB and Fastboot" application previously installed in your Windows PC. You will access to the command window (dark background) for scripting.

8.1.- Type "adb devices" to check if your device is recognized. If that's the case, an alpha-numerical code will appear signaling your phone is successfully identified by Windows and ADB. For example:

C:\Program Files (x86)\Minimal ADB and Fastboot>adb devices

List of devices attached

32F476848526 device

If you don't see the alpha-numerical identification number, stop. Reinstall drivers again until the system plentifully recognizes the smartphone. In Windows, go to "Control Panel -> Device Manager" and verify the dispositive is identified not only as a "Portable Device" but also as an "ADB Interfece". For more information go here.

8.2.- Type now the following command in a single line (copy and paste if wanted):

"adb shell dpm set-device-owner com.catchingnow.icebox/.receiver.DPMReceiver" (remove exclamation marks)

At this point in time, "Ice Box Pro" must have been installed in the phone for this code to take effect. A statement will appear in the command line confirming the script assignation on your device. If you got an error, make sure all your Android accounts are dismissed, that is a mandatory sub-step.

9.- Reboot your phone then add your accounts back again as usual.

10.- Run "Ice Box" and select, finally, configuration as "Local Administrator". Now you have grants to freeze apps and services at will, just as if you were vividly rooted.

11.- Get now rid of all bloatware and useless services (about 95% of all active script load). In "Ice Box", go to "System" tab, then in local "Settings" (three vertical dots) check "Include Hidden". You will see now the full list of apps and services in use. Freeze the freaking list out! That is what makes the phone performing like garbage! Just make sure you have the following critical services active (not frozen) at all times in order to prevent soft bricking:

(1) Google Account Manager,

(2) Google Keyboard,

(3) Google Services Framework,

(4) Media Storage,

(5) Package Installer,

(6) Android Launcher (active by default if you don't see this one in the list)

The rest can be safely disabled (frozen) without the risk of boot looping. Those are the very bare minimum required services for minimal operation, though. If you want, for example, telephony service enhanced, you will need also to activate (a) Data Service, (b) Dialer, (c) Contacts, (d) Contacts Storage, (e) Messages, (f) MmsService, (g) Phone and Messaging Storage, and (h) Phone Services. If you want, lets say, GPS enhanced, you will then need to activate Fused Location service as well. If you want to connect to your PC you'll need MTP Host active. If you want to run Google Play and download apps, you will need (a) Downloads, (b) Google Play Services, (c) Package Access Helper and (d) Package Installer, and so on and so forth for other tasks and duties. Get familiar with all service functionalities so you become skillful to know which ones to turn on and which ones turn off at any given time at any given task. Rule of thumb: the minimal the services active the fastest the system becomes. Both "Google Play" and "Google Play Services" play a major, I repeat, a major role in draining the battery - along with the LED brightness - , so try to keep them both at bay by freezing them as much as possible.

12.- Enjoy!

I'm about to try it on my phone wish me luck

, Kalius