[Galaxy S 5 Q&A, Help & Troubleshooting] Georgie9117:
Hi mate, I'm here again! :)

Unzip those files that mentioned my pervious post and copy to the SD card all of them except AFN6 ROM.

First of all: backup anything you can - not only to the memory card, copy them all to PC for more safe. This operation will wipe absolutly everything from your device.

Remove all SIMs and SD card - then go.

1; switch off the phone, start with recovery and wipe cache and wipe data/factory reset then switch off;

2; step in Download mode;

3; start ODIN browse to [AP] the unzipped ROM file (G900FDXXU1ANF6_G900FDOJV1ANF4_G900FDXXU1ANF6_HOME.tar.md5) and wait while it checks;

4; connect the phone to PC (in my case ODIN not shows the connected device only the eventlog writed 'Added'), then if everything right click START;

5; at first start of KitKat ROM choose your language but skip all next settings (switch off Wi-Fi) just go to settings and done the followings: in About device/Software update OFF (unthick), back to About device find Build number and tap it 7 times to enable Developer settings, back and step in the Developer settings and thick the USB debug mode, back and go to Security here thick the Unknown sources and unthick Disable reactivation;

6; now switch off, instert the SD card, switch on and connect Wi-Fi (towelroot needs internet connection) (some updates will arriving but no install them!);

7; install towelroot, run it and click 'make it ra1n' button (it will success /it writes: Thank you for using Towelroot. You shold have root no reboot required.../ but if not (get this: Phone not suppoted/ you have bad ROM or some update installed - it's not good, you can go to the first step);

8; install SuperSU, run it, update binary + allow to disable KNOX, then restart;

9; install FlashFire, go its options, thick 'Freeload', then to the Actions and click on the red circle with '+' character and choose Flash firmware package, browse unzipped BOE2 ROM from the SD card, wait for check, thick the partitions: 'Boot', 'Recovery', 'System', 'Cache' and 'Preload/Hidden' but no check the protected ones, back with thick on the upper right side, int he Process Cache section thick 'Enable' and 'Allow Cache wipe', in EveRoot menu thick 'Insert SuperSU', 'Enable ADB' and 'Perserve recovery', in the end Reboot menu choose reboot typa after flash ('Normal' will be good);

10; tap on the flash icon to proceed.

The display go black two times, but no worry, it's okay. The operation needs 2-3 minutes to be ready, reboot automatically at the end. After that boot the Lollipop like first start, but the root remains with SuperSU. Now you have rooted Android 5.0 on your S5 Duos plus KNOX=0x0.

Some hints...

If SuperSU not works (at step 8), make full wipe and install again SuperSU but it's advised btw here - I made it.

I like clear things do I have clicked in FlashFire wipe internal storage.

Be careful when moving files to the SD card use safe remove function to avoid corrupted files or copying errors.

There are some additional steps, like flashing secured partitions, change bootloader to see SAMSUNG GALAXY S5 Duos (instead poor SAMSUNG GALAXY S5 :) ) at boot, enable to custom apps can write external SD card... In my case these are done and works.

Now I'm waiting for your response.

Sorry my bad english...

G.