How to Correct "Not Allowed In Userbuild" Error
Some android devices, either android tab or phone gives "Not Allowed In Userbuild" error message while trying to change the IMEI using either Mobile Uncle, MTK EngineerMOD or any other applications.To an error as such, only two things could be the problem and they;
1- It could be that the phone is not rooted.Since we have known the two (2) major possible reasons, we would discuss the two solutions now.
2- It could be that the NVRAM partition is protected.
Solution 1: Root the Phone
Although, the IMEI of some android devices can be changed but not all. If your android devices is not rooted and you experience errors such as "Not Allowed In Userbuild", your first option is to root the phone.
You may visit this page here for tutorials on how to rooting some android devices.
Solution 2: Overwrite the NVRAM Partition
If no application succeeds in re-writing any android device IMEI even having rooted it, it is most likely that the android device NVRAM section is protected.
This method can be used to change any android device IMEI for as long as the application is installed on the android device except HTC Androids whose IMEI can be changed using Windows Command Prompt or Linux Terminal.
How to Do It: Using this Method
1- Download the Modified NVRAM Backup from Here: I have uploaded a backed up IMEI and can be downloaded from here. The backup was made with Mobile Uncle application but you can use any application that supports .bak files to restore the IMEI on your android device.
The downloaded file should be place on the internal storage of the android device for best performance.
NOTICE:2- Download And Install Mobile Uncle On the Phone: if you do not have mobile uncle installed on your phone, you should download and install it from Play Store.
- The backup ONLY works with dual-SIM android devices.
- When flashed/restored on an android device, ONLY the SIM2 will change to BlackBerry IMEI.
- This method works better on rooted android devices.
3- Lunch Mobile Uncle Application: lunch mobile uncle application on your phone and locate the IMEI Backup Restore (MTK) and Click It.
4- Select the Storage with the .BAK File: Mobile Uncle automatically scans your phone for all the available .bak files and brings out the list. Simply select the one you wish to change to.
NOTICE:5- Wait for the Success Report from Mobile Uncle and reboot the phone.
- the one SDCARD without any figure behind it is the one on your phone's internal storage. This is your preferred choice in case you have more than one (1) .BAK file on the phone.
And by that, you have successfully change the IMEI of your android device. You can confirm it by dialing *#06#.
Good luck.