Several minutes after creating this account, the game has stopped giving me the 'email is already used for account linking' error message and continued on to asking for the password.  So far, every time I try to enter the password it gives me a "Server error" message.  I'm hopeful that this, too, will eventually work.

Found the solution.   Go to https://neocoregames.com/en/registration and create the account with the login you're trying to use on xbox or PS.    Put in the passwrod and everything.   You'll get an email notification (check your junk too).   Activate it.   Go back to your xbox on playstation and then put in the same email and password and bam...all is fixed.   

Workaround:

- Go to setting of your profile on page.

- Change email.

- Confirm to the change on your email.

- Use new email to link it in the game.

- Now change back to the old mail in the settings - if you want.

After you create the neocore account, just wait a couple minutes, and it will work. Enter your email address, if fails go make a tea, once back press next again, if still fails, go make some sandwiches, and then try again. This time it should work :D

This is down right insanity forcing people to use a broken sign-up process that LITERALLY renders the game unplayable.

I've emailed support and still waiting for an answer.

I bought this game on xbox, before that I bought and played it on steam but on xbox I can't play because I can't pass the f***** authorization, I always have a neokore account but on xbox I can't log into my account because my the mail is always busy with someone (spoiler - it's me), can it be fixed somehow or help me, maybe I don't understand something?

Is this still happening? I'm getting this right now. 

Update: 4 restarts was just the right number to get past this problem. Not sure if me or software, but happy to be playing.