Did you tried to roll back from B511 to B326 but you fail .... try what I did here

Hi everyone,

this is the absolute way to roll back from Marshmallow B511 to any previous version whatever it's a lollipop or kitkat.......

(As usual the risk is on your responsibility)

*******This Method is tested only on MT7-TL10 (Please don't try the files on this thread on different model number ********

Files you may need:

1- Roll back from lollipop to Kitkat (this is the trick)

DRIVE
LINK

UPLOADED
LINK

MEGA
LINK

2- for me i tired with kitkat rom B119 sp03

LINK

3- extract all file from B119 Sp03 and be ready to flash all of them via (fastboot)
(so may unlock your bootloader and you should have all files for adb and fastboot)
*recovery
*boot
*cache
*cust
*system
*userdata
it's an easy way, no need to change the location or make any special things \\\

download the rollback file which I mentioned before, put it on dload on the extSdcard, and make a local update ( if local update not showing for you try a search for HwOUC.zip and flash it with Twrp recovery)

after you make a local update the roll back should complete 100% because this file is the only roll back that compitable with B511

then put what you want kitkat or lollipop rom ( for me I tried with B119sp03 kitakt and it's fail on 40%)

now enter the bootloader mode and flash all img's for the rom which you tried to flash

after finishing it opne on a stock android, so no issue try a factory reset and everything will be normal after that

Download from this link