You can use the odin to flash TWRP 3.1.1 on your Grand Duos, so you can flash Lineage 13 (remember to untick the "auto reboot" option), when it appears the "Pass", you hold Power, Up volume and home to go to the TWRP, and just follow the same instructions (wipe everything except Micro SD, flash system, flash gapps and boot up) but i recommend CM 13.0 https://androidfilehost.com/?fid=457095661767124300 because every time i try to flash Lineage 13, i get stuck at bootloop
Thanks a ton for your quick reply and helpful advise.
If I could get some more info that would be great!
I want to know what odin is. Is it an android debugging bridge like ADB and fastboot? If yes, then why can't I flash TWRP .img file directly on the Galaxy Grand Duos using the ADB command window after connecting the device in fastboot mode to my PC?
Correct me if I'm wrong. I have myself flashed LOS 14.1 on my Xiaomi device and that went very smooth. So I'm a bit confused over why the TWRP installation methods are different for these two devices. Just because mine is a newer device? God knows.
You were advising me to flash the last build of the year 2016 by osas cuz you faced boot loop with the newer build.
Can you tell me on what build you faced the bootloop?
Was it the latest 2018 build or the build prior to the latest 2018 build i.e. the 2017/07/20 build.
Cuz people here are advising not to flash the 2018 build cuz it has got bootloop issue. They say that you can safely flash the 2017/07/20 build which doesn't have the bootloop issue.
So what build caused bootloop in your device?
I thank you again sincerely.
I'm gonna flash it today after I get your reply.
P.S. On the official TWRP website i.e. twrp.me I came across a term called .tar file which has to be flashed via odin in order to get TWRP installed. I've attached a screenshot from their website. But why isn't there a .img file? I flashed a .img file on my Xiaomi device via ADB by writing fastboot flash recovery twrp.img in the command window of the ADB folder after connecting my device in fastboot mode to the PC and I got TWRP installed.
Sorry if you think I write too much.