This firmware is for Alcatel OneTouch Pop 4 Slate (5051D). After downloading the firmware from below link, unpack the archive and flash with tool / instructions at the end of this post.
Alternatively, you can flash with SUGAR QCT_SP by extracting the flash files to …\SUGAR QCT_SP\bin\ directory in your SUGAR QCT_SP installation path.
File Name: 5051D-2DALRU1.7z
Size: 922 MB
Firmware Link – Download
SUGAR QCT_SP – Download
If you have problems flashing this firmware or prefer to flash the deodexed firmware (already has all bloatware removed), visit this link https://www.leakite.com/2017/09/download-alcatel-onetouch-5051d-pop-4-slate-stock-firmware-flash-file-deodexed.html
After unpacking the firmware as explained above, launch SUGAR QCT_SP and install the drivers.
Copy the firmware files to …\SUGAR QCT_SP\bin\
Connect the device and follow on screen instructions to flash.