Solved
Impossible to get Grim's Guitar due to birthdate error.
On the newslatter page it says next to birthdate 'YYYY/MM/DD' I therefore cannot click 'Get Emails & Grim's Guitar' as it won't let me because it is wrong. The site needs it to be in 'MM/DD/YYYY'.
I have tried to edit my birthdate yet when I went to edit it, nothing was wrong and was displaying the correct MM/DD/YYYY.
What is going on?
Why is it saying it is wrong when I literally cannot change it?
Thanks for attempting to help!
The issue was with the website itself being buggy. The site has been fixed now so the bug no longer occurs.
