Hopefully this might help someone who comes across a similarly bizarre situation. I've gone into detail to ensure anyone who tries this has all the info needed, so apologies for the biblical post but this 100% worked for me on my S6.
Ok, so here's the dilemma I was faced with which was a total nightmare. My phone (although otherwise fully functional) was slowing down a tad and becoming quite laggy so I decided to factory reset it (as I've done a hundred times before to several phones over the years). All the usual pre-requisites were carried out (back-ups taken, usb debugging on, reactivation lock cleared, etc.) I proceeded to factory reset the device, all went as expected without any issues. Once completed and at the 1st setup page, I selected language and proceeded. I set up WiFi connection and proceeded. I was then met with the next setup page, my Samsung Account. However, there was a message - "This device is locked because of an abnormal factory reset. Sign in to the Samsung account that you have already signed in to on this device to confirm that it belongs to you." Well, I naturally proceeded to enter my Samsung ID and correct password, but that's when things got weird. After a longer than expected period to sign in, I got a brief pop-up to say "Processing failed". That was it, no other explanation, no other option, no other way around it. I was now 100% locked out of my phone which I have had (store bought from brand new) for 2yrs. I contacted Samsung support, but I think we all know that was a complete waste of time - so I began to research extensively. I came here to XDA first but couldn't find any solution, I then scoured the web and checked a tonne of YT videos. Again, nothing doing - it was all either outdated information, Samsung had patched vulnerabilities, or the methods were just time-wasting idiots posting hoax fixes which did nothing. It was worth it to a point though because I got several tips and picked up some software. Then after about 8hrs, I stumbled across another post from someone here on XDA https://forum.xda-developers.com/verizon-galaxy-s6-edge/help/reactivation-lock-bypass-samsung-account-t3625723#post73617288. Massive thanks to him/her. The basis of his/her method definitely works, but I had a few improvements, particularly concerning the dialling of emergency numbers. So, that's the background to the issue I had and how I got to here. The following is the full method of what I did and I can say that I have a 100% fully functional S6 again. I've gone into this detail as I've found that a lot of posts can be a bit vague, so hopefully this helps someone out....
1. On the 1st setup wizard page after the factory reset has completed; select your language, then connect to (WiFi preferably). You then arrive at the Samsung Account sign-in and cannot proceed any further.
2. Make sure that your phone is NOT connected to your PC at this stage and just for clarity - also make sure than your SIM card is still in your phone. (Some instructions say to remove it, don't do that if you want this to work.)
3. Leave your phone alone for the moment.
4. Ensure that 'Samsung Drivers' for your phone are installed on your PC. (If they already are - great. If not, install them so that when you eventually connect your phone to your PC later, you can see it.
5. Next, download the terminal program here: https://drive.google.com/file/d/0B4OYgE4A8WCzckpyTDVuODc4TWs/view It's called Realterm and is only about 12MB. (There are other newer versions of this available, but this one worked for my purposes.) Extract the program and install (running it as Admin) and ensure that all 4 boxes are 'ticked' as you install (i.e. usually 'source' & 'DLPortIO' boxes are un-ticked, so put a tick in both and then complete the install. As the install completes, un-tick both boxes 'Register' and 'Show ReadMe'. Done. You should now have 'Realterm' icon on your desktop.
6. Back to your phone now. With it still stuck at the Samsung Account sign-in window (or any preceding window), connect the phone to your PC. If an 'installing drivers' pop-up appears on your PC, wait for the Samsung driver to finish installing. If on the other hand, you phone connects to your PC straight away, then proceed straight to 'Manage'. (i.e. Right-click on 'My Computer', select 'Manage' and select 'Device Manager' from the left list. Then in the main window select 'Modems', then right-click on 'Samsung Mobile USB Modem' and select 'Properties'. Hit the 'Modem' tab at the top and simply note the Port. It should be Com & a number, for example 'Com3'. Once noted, you can now close all 'Manage' windows.
7. Open 'Realterm' from your desktop icon by right-clicking and running as admin. (a) On the 'Display' tab, ensure the 'Half Duplex' box has a tick inside it. Don't mess with any other settings here. (b) Then hit on the 'Port' and ensure that the port number you noted from #6 above is selected. If it's not, select it using the dropdown option and once selected, apply it by hitting the 'Change' button with the green check-mark to the right. (c) Once completed, then hit on the 'Send' tab. Open the extracted folder where you installed the terminal program from (#5 above) and open the 'code.txt' file. Copy/paste the first line of text to the very first blank box (i.e. directly under the tabs 'Display', 'Port', 'Capture' etc.) Then hit the 'Send ASCII' button. You should see the pasted text in the black terminal window above, followed by 'ok'. Now remove the pasted text and copy/paste the second line from the 'code.txt' file to the exact same location. Again, hit the 'Send ASCII' button. **Now, quickly look at your phone screen as it should be attempting to make a call to a dead '900' number. You need to be quick, but cancel the call by hitting the red phone symbol and 'quickly' hit on the 'Message' button as if you were going to send a text.
8. You should now arrive at a screen where you can send a text message to the dead number 900. In the text field, type 'www.google.com' and send the text. The text goes nowhere, but now you've created a hyperlink to Google that you can follow (as long as you have WiFi on). Follow it by clicking on the link and you arrive at Google home screen.
9. Search for Package Disabler Pro 9.8.
10. Download it and install it.
11. After installing, you might get a pop-up window to say that PDP Engine needs to be installed in order for Package Disabler Pro to work. If so, install that too.
12. I also found that searching for and installing ES File Explorer was hugely beneficial, because (a) you have extremely limited functionality on your phone (i.e. you can download the programs, but can't just pull-down from the top of your screen to select them as you may be used to doing. As in, they install, but may not be easily selectable so you have to navigate to their location to run them and (b) now that you have partial access again via Google, you need to be careful not to lose your window of opportunity.
13. So, once you've downloaded & installed #9, #11 (if needed) & #12, open Package Disabler Pro.
14. Search for "Samsung account".
15. Once found, click on it, 'Clear Data' and then 'Disable' it.
16. Go back to Google now and search for QuickShortMaker.
17. Install it and open it. (You may need to use ES File Explorer to be able to navigate to it and open it.)
18. Within 'QuickShortMaker' > 'Incremental search' > 'Activities'; search for "Setup Wizard". It should be near the bottom. There are lots of setup wizards once you find it so pay close attention to specifics here.
19. Select the one with ".setupwizards.SetupExitActivity". (It's near the bottom of that particular screen but again, you need to pay attention to the small print and ensure you select the right one.)
20. Once you find it, select 'Create'.
21. Done! You can now restart your phone and after you select your language, then connect to WiFi, you will bypass Samsung Account and gain full access to your phone.
After this you can go and check that there is no Samsung account displayed (i.e. Settings > Accounts). There won't be, but you won't be able to add one at this point either....
1. Go back to Package Disabler Pro and re-enable the "Samsung Account" option.
2. Go to Storage (Settings > Storage) and clear all cache.
3. Go to Find my Mobile (Settings > Lock screen and security > Find my Mobile) and from there you should be prompted to insert your Samsung Account details to successfully add your Samsung account.
4. Once completed, you can either choose to do a Factory data reset (from within 'Settings' > 'Backup and reset'. NOT from recovery. Or you can simply restart your phone if you don't need a factory reset and you should be good to go.
5. Done, now you should have your Samsung account registered to your phone and can sync with your account.
This is what worked for me anyway and gave me full access back to my S6 running stock 6.0.1.
I've tried to be as detailed as I could with this post to ensure all necessary steps are there to follow. It may seem daunting to some before you try it, but I assure you it's relatively straightfoward and I had no problems. I hope someone finds it helpful and it recovers your S6 too if you get stuck in a similar situation to me. All the best.
