The page didn't cause the issue. You used a different email address than the one that you used for your COD app account and that has caused the app to go haywire. Unlink your account and relink it to your original COD app email address and you should be fine. The COD app can't handle email address changes and does this every time someone tries to change it.
He's right. This issue happens when your gamer tag is not linked to the email address you used when you started or joined your clan. Best advice would be recall the email address you used when you started or joined your clan and link your gamer tag there.
Good luck. Hope this will help.