Galaxy S6 - Can't unlock phone after factory reset
Ok, I finally got a solution to my problem, this is obviously a Samsung bug in their software because I can't unlock my phone with the legitimate Android account. The following method works for unlocking any Samsung phone which is good and, at the same time, bad because a skilled enough thief can unlock your phone (although he won't have access to the data because the phone must be wiped).


Download Miracle Box, at this time 2.58 is the latest version.
Put your phone in Download Mode and connect it to the PC.
Open Miracle Box and go to the Samsung tab.
Select the Reset Reactivation/EE Locks and click Start Button and wait for it to finish.
Your phone won't boot now, download a stock Samsung ROM with the same version as you had. I had Nougat so I have to download that, don't try a lower version because the bootloader won't allow you to flash it.
Use ODIN to flash the new stock ROM.
You should be able to boot your phone normally without entering the Samsung account.


If you think this is too much for you give UnlockJunky a try. It was going to be my last resource.